Results matching “czekanski”

Ants and Disease

Hello, this is a very strange situation but I have a 10 month old baby in my home and I am concerned.

A couple of weeks ago I went in to the backyard and noticed my dog was playing with something unfamiliar. As I walked towards it I realized that it was a bird. This bird must have been there for awhile because it was unable to move, and had defecated so much that ants were (I'm sorry for the graphic details) actually crawling inside of this poor bird and apparently eating the fecal matter. This poor guy was obviously in a significant amount of pain so we had to do something very sad to stop it from suffering any longer.

This just so happened to have occurred next to a wall in our home that is the exterior wall to our dining room where we eat and where my 10 month old's high chair is. Today, I was eating at our table and some of my paper work and pens were sitting on top of it. As I was picking up my plate I noticed the same species of tiny little ants crawling all over the table and my paper work. There was not even any food or anything on the table that could have lured them there. I instantly took my son upstairs, and began disinfecting the table, vacuuming and such.

I do not know anything about ants but my concern is that these ants might be carrying disease from the bird. Can you please tell me if I need to be worried about this? They are the tiniest little transparent orangish colored ants. We live on Oahu, in Hawaii. Thank you very much for your time.


Ok, Alix. I've got good news and bad news.

The bad news: Ants (just like any animal that moves from one place to another) can transmit infectious bacteria, including Salmonella and Staphylococcus. (I'm not trying to throw your dog under the bus by any means, but your dog is definitely more of a vector for bacteria coming in from outside than these ants.) As indicated in a quick literature search (click here ), it's been reported at least as far back as 1914 (Wheeler) that if an ant walks through an area densely populated with infectious bacteria, they track it along in quantities large enough to show up in a petri dish.

The good news: Petri dishes don't have immune systems. The quantities of bacteria ants transport and slough off as they saunter across your counter tops will probably be small compared to the infectious dose for healthy humans. The quantities of bacteria that remain on the ants' feet after taking the thousands of little ant-steps between a source of infection and your table would presumably knock off the vast majority of the bacteria, leaving too few to constitute an infectious dose.

So what I'm trying to say is: thought it is theoretically possible for ants to transmit infectious bacteria to humans, as far as I'm aware (other members of this blog, please speak up if you know better!) there are no records of ants being definitively implicated in someone catching a disease. As best as I can tell, all of the articles that reference ants' potential to be vectors for infectious bacteria are based upon laboratory studies in which nothing besides some agar in a petri dish got sick. Ants, as you know, are quite common, so it seems to me that if they were serious actual (as opposed to potential) disease vectors, we'd have heard about it.

A well-intentioned tangent: This is, of course, neither a child-rearing nor a health advice blog, but I think this recent article on the "Hygiene Hypothesis" makes a good case for not keeping too sterile a house:
Some arguments, both pro- and con- Hygiene Hypothesis haven't been rigorously scientifically tested, so take everything you read with a grain of salt...or a pinch of dirt.

Hope this helps!
Jesse Czekanski-Moir & the AntAsk Team

When comparing human infrastructure and ants what would you say is their most common behaviors? Do you think there is anything humans could learn from ant behavior?

Dear Jacqueline,

When human designers, architects, engineers, and computer scientists turn to other organisms for inspiration, it is often referred to as "biomimicry." In recent years, more and more people have turned to the other species on Earth for inspiration. Recent and ongoing work in Biomimicry is highlighted in this TED talk (by the main popularizer of the term "Biomimicry").

However, the speaker doesn't mention much about ants (and neither have I, so far...). One of the reasons ants are so interesting is that they display a wide variety of life-styles, from farming fungi, to raiding termite nests, to foraging in the shifting sands of the desert. And they're able to do all this with very little of what I would call "individual-level intelligence." Ants, like other social insects, function without central control, using what has been referred to as "swarm intelligence." (for more of my ramblings on swarm intelligence, see a previous post here, and also this more coherent article from National Geographic).

So, by studying ants and other social insects (like bees, termites, and certain wasps), we can learn more about true, blind democracies, and how to get things done without central control. For example, by studying processes different kinds of ants (and other social insects) use to find food and tell each other about it, computer scientists and engineers have been inspired to think of new ways to route traffic, solve resource distribution problems, and perhaps even program robots. The tricky thing about biomimicry right now is that many of these are still just potential lessons we could learn from ants - they haven't yet changed the way we get things done in our own lives.

The other tricky thing about biomimicry is that, like things you read in a blog post, sometimes what seem to be cogent lessons need to be evaluated and taken with a grain of salt. For example, in this article, the author uses the example of fungus-growing ants as a system of agriculture that we should learn from (perhaps just because of that charismatic image), but in the same paragraph alludes to the dangers of monoculture, which is exactly what fungus-growing ants (and termites) do: they cultivate a single species of fungus. They can get away with it, because they've evolved the ability to secrete antibiotics and fungicides from glands in their bodies, and they have the labor power to strip acres of vegetation around their nest and bring it back to fertilize their gardens (the most charismatic ants that farm fungi are the leaf cutter ants; other types of fungus-farming ants and termites use some combination of things like soil, partially decayed vegetable matter, the exoskeletons of dead insects, and caterpillar frass to fertilize their fungal gardens). Worse, there are different kinds of ants that make slaves of other ants, ants that are very lazy (surprise!), and ants that just hang from the ceiling all day collecting sugar water in their abdomens (which I would probably try for a while, but might lead to diabetes after a few weeks). So just like the Japanese scholars studying at the "Institute for the Study of Barbarian Books" in the 1800s did with knowledge from "The West," we should study nature (ants included), but pick and choose which lessons to incorporate into the society we wish to build for ourselves.

Hope this helps!
Jesse Czekanski-Moir & the AntAsk Team

Can I train ants? (Ryan)

Hello Antblog,

I am interested in conducting some experiments with ants and I had a few questions I'd like to ask before I get started and I thought your site would be a good place to start.

1) Can queens of different varieties be trained(forced) to co-exist in one colony if an abundance source of food is present?

2) What is the smartest breed of ants?

3) Could ants in an ant farm learn to farm aphids? How might I go about doing this?

4) Could ants survive on honey alone?

5) Could ants be trained to use little man made tools for things such as cutting or digging through rock?

6) Can ants smell and identify different metals such as iron, nickel, gold, etc.?

I understand these questions are very vague and I do not expect a direct answer for all of them, but any information is appreciated. I'd even like additional links I could go explore myself.
I am only a grade 12 student but I am very interested in ants. My ultimate goal is to create a super ant farm to test the capabilities of ants as well as teach them to advance as a species.

Hi Ryan,

I apologize in advance: this post is probably too long and too speculative. The answers to a few of your questions are simple: (6) I don't think so; (4) some ants can; (3) it's thought that this is not a learned behavior, but some ants do facultatively tend aphids; (1) no, unless they are social parasites (for more stuff on social parasites, click here, here, and here).

Questions #2 and #5 are pretty complicated, philosophically and biologically, so I'm going to spend most of the rest of this post talking about them.

But real quick, before I dive into a heady diatribe about the philosophy of psychometry: ants and honey:

Could ants survive on honey alone? Adult ants don't need very many nutrients, and can survive for at least a week or two (often more) on just sugar water or diluted honey. It is the egg-laying ability of the queen, and the growth of the larva that depends on more protein-rich food sources, like (depending on the ants) seeds or insects. Several groups of ants seem to have bacteria living in their guts that can help them make nitrogen (one of the important building blocks of life that we need to synthesize proteins), but I'm not sure if anyone has quantified how only raising these ants on carbohydrates influences how many eggs the queen can lay, and how fast the larvae can grow. For many ants, we don't know their exact dietary requirements, but by and large, the ants that are most likely to be able to get by on a sugar-water or honey-only diet are arboreal (spend most of their time in trees). Carpenter ants (genus Camponotus) and Acrobat ants (genus Crematogaster) are among the most likely candidates that you'd run into outside of the tropics. Similarly, with respect to your question (3), many of the same ants that are largely herbivorous will occasionally tend aphids or other related phloem-sucking insects. But I'm not aware of a learning component to this behavior: I think it's hard-wired.

Okay. Onwards and upwards.
You know, when I tell people that I study ants, I am often asked (by males especially) if I am working on weaponizing them or figuring out how to harness them for industry. Ants are, after all, famously industrious. There is even an ancient Greek/Indian/Russian legend about ants that mine gold (sort of). I read about it in the book "Shalimar the Clown" by Salman Rushdie (which is a great novel if you're interested in 20th century geopolitics, but doesn't have much useful information about ants).

In general, the major hurdle to training ants for any specific anthropocentric end is the way in which they actually get things done. Deborah Gordon has a really nice book about ant behavior called "Ant Encounters" that I highly recommend. One of the key aspects of ant behavior she does a really good job explaining (not least because she pioneered this research) is "emergence." Her research, and the research of other people who study social insects, is much of the inspiration towards work in "Swarm intelligence" in robotics and computer science. Basically, the problem-solving ability of the colony, or "intelligence" does not arise from the leadership or intelligence of a few ants, but emerges from the trial and error of many non-intelligent individuals. Thus, to train a swarm, you'd really need to understand how voting works in these true, blind democracies. Here are a few links you can check out if you want to learn more. Deb Gordon and Tom Seeley are some of the most eloquent speakers and important researchers on the biological side of swarm intelligence (read/listen/watch more here, here, and here).

The most compelling examples of humans modifying ant behavior are not the results of training, but of trickery. It's easy to get ants to walk where you want them to walk, think a given nestmate is dead, and become alarmed by isolating one of the pheromones they use to communicate, and applying it in the right way. However, I can't think of a way in which you could use pheromones to trick ants into picking up tools, or finding gold, unless you could splice the gene for pheromone production into a bacteria that preferentially grew and expressed that gene in the presence of that metal. This is not completely implausible, and as we learn more about the genomic architecture of ants, and the metabolic pathways involved in pheromone production, using a genetically-modified bacteria-ant system could potentially become economically viable (and probably less ecologically destructive than most current mining techniques). One could aerially spray genetically-modified bacteria over an area that already has high ant densities, using the bacteria to trick the ants into collecting soil particles with high concentrations of metal oxides. Then, a few months later, when the ants have collected the clumps of soil with the most metal oxides, one could find large ant colonies and spray another strain of genetically-modified bacteria directly into the nests, that would make the "dead ant" pheromone in the presence of high concentrations of the metal oxide. After a few days, one could go around collecting the midden piles at the surface of the nest, which would be enriched in the target metal oxide. This sort of strategy would probably work best in desert or grassland environments, where a few species of ants build conspicuous nest mounds, like Pogonomyrmex in the American Southwest. It's possible one might be able to do this chemically, without genetically modified organisms of some sort, but if there was a much simpler way of using ants to work for us, someone (especially in Greece, Russia, or India) probably would have figured it out.

Beyond pheromonal trickery, it is possible that we'll be able to eventually trick ants electrochemically, as you can "currently" (get it? like, electrical current?) do with cockroaches:
It's possible that, by controlling one ant with electrical impulses, you could convince the rest of the colony to do your bidding. However, as Tom Seeley found with bees, nestmates might need to be convinces themselves of the validity of the scouts choice, in which case you'd need to coordinate quite a few ants to agree that, for example, a vein of gold is a food source. The trickery arguments above apply primarily to ants that often recruit to a food source; however, there are ants that primarily hunt alone.

As you may have figured out by now, your question "which ant is most intelligent?" depends on what kind of intelligence you're talking about. The types of ants most likely to exhibit high degrees of swarm intelligence are the ants that form the biggest colonies, and need to forage collectively. Leaf cutter ants (especially Atta and Acromyrmex) and army ants (especially Eciton and Dorylus) form colonies of hundreds of thousands of individuals in the wild, and many types of invasive ants (such as the Red Imported Fire Ant, Solenopsis invicta) form sprawling super-colonies that can cover acres in their introduced ranges. I'm not aware of a "swarm intelligence" test (but see Seeley's work on, for example, nest-finding abilities of honey bees in Maine), but the number of worker ants involved, the foraging range of the colony, and the complexity of the environment would all likely factor in. It would be interesting to compare how quickly swarms of different sizes and species could solve a maze, for example. I'm not aware of a study like this: perhaps you could set something up!

Observations of ants in the wild can allow one to make at least cursory qualitative statements about swarm intelligence in ants. The complexity and scale of leaf cutter ant nest architecture, the many tasks involved in maintaining a fungal monoculture, and the hazards of foraging in tropical savannas and forests leads me to suggest that the attines may exhibit the highest degrees of emergent, swarm intelligence, perhaps surpassed only by the fungus-growing termites of the African and Australian tropics. A foraging swath of army or driver ants (Eciton or Dorylus) may be collectively be processing millions of environmental signals per second: scent and vibrational cues about proximity of prey and colony members, light ant dark cues, etc., which is similarly impressive.

Basically everything listed in the paragraph about ants here (and the suspiciously similar list here) is a result of "swarm intelligence," and not at all related to the individual intelligence of any of the colony members. Personally, I don't think there is a clear winner between ants and termites in terms of the complexity that emerges from the swarm intelligence of their respective superorganisms. And I'm somewhat tempted to write a whole 'nuthur blog post on what is wrong with these two articles... perhaps some other time.

So far as individual, organism-level intelligence goes: again, I can only speculate. I am tempted to guess that the ants that have small colonies and have large workers that forage by themselves are most likely be more individually intelligent, because colony fitness will depend to a greater extent on the problem-solving ability of ants acting individually, rather than the emergence of intelligence from trial-and-error and blind democracy. Conversely, I would expect very small ants that live in very large colonies to be the least intelligent, individually, because, as a colony, they can rely on swarm intelligence to effect reproduction. In primates, the "social brain hypothesis" (also, see here) suggests that group size should be positively correlated with brain (neocortex) size. An assumption this hypothesis makes is that intelligence is necessary to maintain group cohesion through diplomacy, strategy, and individual recognition. In most social insects, group cohesion is pheromonally-mediated, so intelligence need not scale with group size. However, in some groups of ants and wasps, there is a shifting dominance hierarchy, which might mean individuals have to remember each other and behave according to past experiences. Elizabeth Tibbetts, to the astonishment of the behavioral and entomological communities, demonstrated face recognition in certain wasps with changing social hierarchies that are reinforced by in-fighting, rather than solitary wasps or eusocial wasps with hormonally-mediated social hierarchies. Thus, the ants that are most individually intelligent (e.g., the most train-able) may be ants that have shifting social hierarchies, and/or spend much of their time hunting by themselves. We're still learning more about the social lives of different species of ants: if you include species that haven't been described or discovered, there are probably more than 20,000 ant species in the world, and many of them have remarkably divergent ways of life. Several species I can think of which have to contend with a reality of changing dominance hierarchies (often due to unconventional reproductive strategies) throughout the lifetimes of individual workers, include ants in the genera Pristomyrmex, Platythyrea, Myrmecia, and Cerapachys. Myrmecia include some of the largest and most visually-oriented ants (two factors often correlated with increased brain size). They are also among the largest of ants, and very effective solitary hunters. So I would guess that some member of the genus Myrmecia might be the smartest ant, on an individual basis. Other strong contenders include ants that forage alone and use visual cues to navigate back to their nests, such as Gigantiops destructor, Cataglyphis, and Melophorus.

"Tandem running," a behavior in which one ant basically takes another ant by the hand and leads them to a food source (actually, they just tap each other's antennae pretty much the whole time) has been proposed as the first example of "teaching" in insects (by their definition, the "waggle dance" of bees is simply "broadcasting").
However, a critique of this article by some of the leading non-human intelligence researchers takes issue with this definition of learning, with implications for how intelligence might be defined (not to mention an implicit critique of the education system). Definitely check out the Lars Chittka's publications page for a veritable treasure trove of readings on insect intelligence.

Not to end on too preachy a note, but your statement "help them advance as a species" is problematic on two counts: (1) ants are a family, the Formicidae, which is comprised of more than 14,000 described species, and (2) "advance" has very strong teleological overtones. Teleology is an understandable (Nietzche was all about it, and would have been really happy with you for using that sort of reasoning). But it's not the way I think biology works. Saying you would like to domesticate ants, or modify them behaviorally or biologically so that they are more useful to humans is one thing, but the advancement of a species is an empty concept. Evolution is change, not change towards a goal.

To wrap it all up: swarm intelligence has many advantages at the colony level, but should not be confused with the individual intelligence of organisms. Without broad, cross-species comparisons of either kinds of intelligence, I can only speculate (perhaps beyond the limits of my own intelligence) about which ant is the smartest. Both types of intelligence would require different approaches to training or other types of behavioral manipulation. If there were an easy way to train ants for industry, someone would have probably figured it out by now. Emerging biotechnologies may make the use of ants (and/or ant cyborgs... cy-ants?) possible, but assembling little robots (equipped with both swarm and individual intelligence) from scratch might be prove to be easier, at least in the short run.

Whew! Was that enough to get you started? :)
Jesse Czekanski-Moir & the AntAsk Team

What does ant dung look like? Cristina


I came across your interesting website and I wanted to find out if there are any images available for what ant dung looks like.

Many thanks,


Hi Cristina,

Thanks for your question! I have to admit, although I've spent a fair amount of time looking at ants, they're usually either dead or foraging: I've never caught one in the act, so this was a fun question for me to try to answer. Luckily, I have access to some other people with lots of ant experience, so I'm able to share their insights.

First, though, let's start with some terminology. When insects eliminate undigested waste, it's called "frass." This is a general term, that also (depending on who you ask) encompases other little particles and exudates that result from insect activities. For example, wood dust that results from carpenter ants gnawing through wood is sometimes considered "frass," even though the carpenter ants don't actually eat the wood - they just cut through it. Since your question is obviously directed towards elimination, we'll focus there.

Something about ants that many people don't realize is that as adults, they are unable to consume big chunks of food. Their jaws are often good at holding and/or cutting through objects, but not well-adapted for chewing food into pieces small enough to swallow. Some ants can eat pollen grains, but solids much bigger than that will not pass through the narrow constrictions at an ant's neck and waist. In a peculiar reversal of the "mamma bird" situation we've all seen on nature shows (and in real life, if you're lucky), adult ants must bring solid foods back to the nest, where the ant babies (larvae) eat it, and then vomit some of the chewed and partially digested food back into the mouths of the adults.

Because adult ants never eat solid foods, their frass tends to be a dark-colored liquid--at least as far as the ants that AntAsk Team members Corrie, James, and Steffi are familiar with are concerned. They (the ants, not the people) also excrete metabolic waste, analogous to urine, in the form of white urate crystals, which James describes as mixing together with the feces in various proportions: "sort of like coffee creamer."

The ant larvae, however, are a different story. They only eliminate waste once during their development, in the form of a dark, compacted mass (can I say "turd" on this blog?) shortly before pupation. This cuts down on diaper changes considerably. Interestingly, albeit disgustingly, sometimes adult ants eat this meconium (reported in Cerapachys biroi by Ravary and Jaisson 2002, and Cephalotes rohweri by Creighton and Nutting 1965). I apologize if you're reading this right before a meal.

As I wrap up this post, I realize I haven't actually pointed you in the direction of any real pictures. There are some pictures of meconia among Alex Wild's excellently curated collection of ant pictures, but I'm not aware of any pictures of an adult ant in the act of defecating. Refuse piles in subterranean ant nests, and below arboreal ant nests are more commonly photographed, but they often contain the bodies of dead workers and discarded prey parts, in addition to frass in the strict sense. So the best I can do is leave you with James' vivid image of a fine white powder mixing into a dark drop of liquid, like creamer into coffee. If I find a good picture of an ant in the act of "frass-ing", I'll let you know!

Hope this helps!
Jesse Czekanski-Moir & the AntAsk Team

ps. if you're interested in other things that come out of ants, please see this previous post about ant pee:

Dear askantweb,

I found what seems to be an undocumented army ant while camping in San Diego County.

Doing my best to remember, I recall these characteristics of the species:


  • Completely black
  • Worker, major worker, and soldier classes
  • 5 cm to 10 cm long
  • Soldier mandibles appear to be able to make an audible snapping sound

  • Behavior:

    • Forms columns at night moving in one direction
    • What seems to be scattered scouts mostly of the worker class preceding the main column mainly observed just after sunset
    • Invades the local termite colonies
    • A number of ants were found to be dedicated to what appears to be guarding an entrance of apparently a subterranean nest at the base of a tree. This was observed during the day and the only instance of observing this specie during the day except when excavating a known local termite colony which was being attacked or occupied by these ants.

    Though it could simply be a carpenter ant, please advise or forward to anyone who may be interested. Thank you.

    Dear Spencer,

    If the insects in question are really 5-10cm long, it's pretty unlikely that they're ants. We have a blog post on how big ants tend to get, and California I can't think of any ants that would be much bigger than 2cm, even if they were a queen.

    There are actually quite a few documented species of army ants from California. The genus Neivamyrmex has workers of different sizes, but they're kind of continuously polymorphic, so you'd be unlikely to think of them as "worker" "major worker" and "soldier." I have a little bit of experience with army ants from the tropics, and I've never heard them really snap.

    The only genus I've heard make an audible snapping noise is Odontomachus, seen here closing its jaws. This genus hasn't been recorded from California as far as I know, but it's possible that the species found in Arizona could make it in SoCal. However, these ants are all the same size as each other, so you wouldn't have noticed distinct castes.

    Carpenter ants, (genus Camponotus) are also large and polymorphic. If you were close to a lot of them, you might have noticed a vinegary smell (formic acid). None of the other ants I've just mentioned would have made that smell.

    Ultimately, I guess I'm stumped. If you go camping again, be sure to take some pictures!

    Jesse Czekanski-Moir & the AntAsk Team


    I stumbled across your very interesting blog whilst searching for an answer about ants.

    We live in the sub-tropics (Queensland, Australia) and just over a week ago experienced severe wet weather (flash flooding) due to an ex-cyclone passing over us. This was after an extended period of dry weather in a hot Summer. We have had a steady stream of various ants come in due to the weather, mostly heading for the kitchen. This is quite normal for us and has been managed mainly by keeping minimal accessible crumbs etc.

    The unusual ant activity we've had is in the last couple of days. One night we suddenly realised that there were clumps of tiny black ants all over the house. There were thousands of them in the laundry, on the top of the wall and cornice - not many down near the water sources at all. There were also about 6 big clusters of them located on cornices throughout our living room and hallway - far from any food source and/or water. The next day another cluster appeared on the door frame of our bedroom en suite - these ones were near some artwork and some were feasting on the glue used in it, but most were in clumps on the doorframe. I took some pictures and have attached them.

    Ants1 is to give you a reference point for size and the shapes of all the small clusters these ants are forming - these are very small ants compared to most others we get locally.
    Ants2 is a closer shot - when I was later looking at the photos I noticed that the ants appeared to be clustered around some sort of larvae or white-fleshed ant? I suppose this is why they are clumping, but am wondering what the white things are. I am hoping it is not termites! I am also curious as to why these ants all suddenly appeared in such unlikely places (and so many times) particularly given that it had been about a week since the wet weather. I would also like to know what we can do to try and discourage them from invading our house in such a huge and sudden manner.

    I've done some searching on ant identification pages etc. and the closest ant I can come up with that they may be is the "black house ant". Although I am not sure they have the right number of joins in their body.

    Any answers to my questions would be much appreciated!

    I can send a bigger sized picture if you require it, just let me know if you do need it. I just didn't want to unnecessarily overload your inbox with a large sized file.

    Thank you,




    Dear Anna,

    Thanks for the question and the pictures!

    First off, these are definitely not termites. Note the "elbowed" antennae and distinct rear part of the body (called the "gaster" in ant literature).

    These ants probably belong to the genus Technomyrmex. They're very common in forests in tropical Southeast Asia and Australia. I used to work on a small group of islands called Palau, and there were parts of the forest where it seemed like nearly every tree had this density of Technomyrmex on them. Although it's tough to say for certain, it's likely that these ants belong to a group of very similar-looking species that would have all been identified as Technomyrmex albipes a few years ago, but have since been shown to belong to several distinct species, including T. difficilis (guess why it has that name!). Here are some close-up pictures of the ants I think you have (although this this ant is fairly widespread, these pictures were actually taken in Queensland). In your region, many common household ants can be identified using a key developed by Eli Sarnat for the Pacific Invasive Ants program out of New Zealand (assuming you have a good microscope). For more complete information on ants in your area, check out our Queensland section on AntWeb, and Steve Shattuck's Ants Down Under.

    We've written a few posts about getting rid of ants in and around your home (for example: here, here, here, and here), but in your case, one of the more important actions might be keeping vegetation from touching your house. I've actually seen a house in Palau that was entirely on concrete stilts, and each stilt rested on a concrete block that had a small moat of water in it - this is essentially the house-level equivalent to putting the legs of your kitchen table in tuna cans filled with water to prevent ants from climbing up. However, the house got electricity from an above-ground wire, and there was a steady stream of Technomyrmex coming in on that wire all the time! So....I guess there's only so much you can do!

    Hope this helps, and good luck!
    Jesse Czekanski-Moir & the AntAsk Team

    What's up with ant evolution? Zoe, Belgium

    Hi guys,

    First of all: this blog is really helpful, great work!

    So now, while trying to write a report on ants --focusing on aspects of evolution-- I stumble upon many many questions. I'm hoping you can help me out!

    1a. Micro-evolution
    I was thinking about invasive species that are nowadays found in several continents, like for instance the Argentine fire ant.. Do all of their populations still belong to the same species? (no subspecies)
    If so, how come? And would a male and female both from a different continent still recognize each other as potential mating partners or not. (If not, what's the term for that?)

    What are specific factors that trigger origination of (sub)species of ants, or what causes the absence of it.

    1b. Macro-evolution.. Can we speak of macro-evolution within the ant family, since there are so many different varieties. If not, could the relation between wasps and ants be an example of macro-evolution or is macro-evolution really about even bigger events?

    2. Sexual selection
    In the mating of ants, is there any 'conscious' selection going on from either gender. Are there species where an individual for mating is picked over another, based on qualities perceived?

    Thank you!

    Greetings :)

    Dear Zoe,

    Thanks for your questions! You've gotten to some really awesome, fundamental evolutionary biology questions here, and you're asking me to make generalizations across a family of insects with more than 100 million years of evolution and more than 10,000 species, so I'm not sure I can do them justice in a blog post, but I'll try!

    Your sub-question under heading 1a: "what are the factors that trigger origination of (sub)species of ants, or what causes the absence of it," is a question that can only be answered in a very generalizable way: speciation occurs when some factor causes populations of organisms to begin separate evolutionary trajectories. Often, as you suggest with respect to invasive species, this happens because of geographic isolation (allopatric speciation), but there are many theoretical and empirical studies that allude to the possibility of sympatric speciation, which is when speciation happens while populations of organisms are still within "cruising range" of each other. A previous blog post elaborates on speciation in the context of nest parasites.

    Your first question about invasive species is great and very timely! There have been at least two studies in the past few years which demonstrated that Argentine ants (Linepithema humile) from different continents actually recognize each other as nestmates! So I can't imagine there would be any trouble with mating there.

    The authors of both papers suggest that nestmate recognition is maintained across different continents because there is a steady stream of new arrivals, which prevents the populations from drifting apart. However, the question of when exactly a speciation event happens is very difficult to pin down. In a classic paper on the "Evolutionary species concept," the icthyologist EO Wiley states that "A species is a single lineage of ancestral descendant populations of organisms which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate."

    By this definition, you would really have to be able to predict the future: how can you know whether a newly isolated population will come into contact with propagules from its ancestral range? The idea that newly isolated populations are incipient species is tempting, but in practice, species can only be delimited if there are morphological and/or molecular differences in them, or, if you subscribe to the biological species concept, things could be argued to be different species if they generally choose not to mate with each other (for more information, you might want to look up pre-zygotic isolation and assortative mating...). In the case of the Argentine ant, I would expect a sudden drop in propagule pressure would result in the actual isolation of the disparate populations, but I would only expect this to happen if humanity drastically changed or ceased its practice of global trade and travel.

    Sexual Selection
    Speaking of pre-zygotic isolation and assortive mating, I think it makes sense to talk about sexual selection in the context of micro-evolution, because that's potentially a pretty important driver of speciation and trait evolution in sexually-reproducing organisms. Stearns and Hoekstra, an often-recommended text in evolutionary biology, defines sexual selection as: "The component of natural selection that is associated with success in mating." While at first somewhat disappointing, I think this definition is useful because it underscores the fact that sexual selection is a component of natural selection. Many ants form mating swarms, or leks, especially in desert and temperate zones. In these cases, there is a certain amount of "scramble competition," and differential levels of mating success have been demonstrated to correlate with individual traits. However, I am not aware of anything approaching the level of mate choice and the resultant secondary sexual ornamentations that has been demonstrated in some butterflies, odonates (dragonflies and damselflies), or other animals.

    For a variety of reasons, the exaggerated secondary sexual traits that seem to emerge in classical examples of sexual selection (i.e., the tail of male peacocks) seem to be less likely to develop in eusocial insects (for a more in-depth perspective on this, check here, here, and here). In lekking species, there is likely to be a very important trade-off between the relative sizes of the flight muscles and the testis and ovaries. Some species of ants do not lek, and either engage in within-nest mating (intranidal mating: for example, some Cardiocondyla exhibit this incestuous behavior), and others engage in "mate-calling," like some moths. For these species, ability to give off (for the females) and recognize mating cues (for the males) is likely to be selected upon, but, to the best of my knowledge, selection on particular traits in these species has not been selected upon. By Stearns and Hoekstra's definition, sexual selection is likely to occur in any sexually-reproducing species, regardless of escalating selection for mate-choice.

    I'll defer to Stearns and Hoekstra again for their definition of macro-evolution: "The pattern of evolution at and above the species level, including most of fossil history and much of systematics." By this definition, macro-evolutionary patterns are evident in any taxon above the species level, for example, the fact that genera such as Pheidole, Strumigenys, and Camponotus have many species, while Paraponera, Tatuidris, and Rostromyrmex have very few species is a macro-evolutionary pattern. More ant genera than usual seem to have arisen when the earths terrestrial vegetation came to be dominated by flowering plants, which is another macro-evolutionary pattern.

    Traits can also exhibit macro-evolutionary patterns: ants are all eusocial - we don't know of any solitary ants. Asexual reproduction has cropped up several times in a variety of ant lineages, but does not seem to have persisted beyond a speciation event. The ability to cultivate fungus has only occurred once in the ants. The processes that gave rise to these patterns are somewhat outside of the realm of macro-evolution, but the justification for using the term "macro-", instead of referring to these patterns as just plain old "evolution," is that they cannot be predicted by an understanding of intra-specific evolution alone. This is analogous to the anti-reductionist argument that cell biology cannot be usefully predicted by chemistry alone--simply understanding osmosis and organic chemistry would not allow us to predict the utility of sexual reproduction, which in some situations can give rise to heterogamy, which in turn drives the emergence of a fertilization envelope, uniparental organelle inheritance, and, in one case, the tail of the peacock. In another case, irreducible patterns and processes random-walked their way to the population of weird little wasps that would become the ancestors of all ants.

    As I said at the outset, one would need quite a bit more time and space to fully answer your questions, but I hope I've at least given you some food for thought.

    Jesse Czekanski-Moir & the AntAsk Team

    I teach at a high school in Australia and I'm currently doing a unit on ants. One of the students in the class lives on a farm where there are lots of black ants. He and his family (I spoke to his father after school and he confirmed that his son was not kidding) have observed that ants seem to know when the rains are coming "weeks, even up to a month before they actually arrive." He says that they start preparing by storing food and building up walls around the nest.

    The class found this fascinating and wanted to know how the ants could possibly know the rains were coming so far in advance. I told them that antweb are an authority on ants and that I would write to you for an explanation. My first question is: Is it possible that the ants could know the rains were coming so far in advance? Secondly, if so, how are they able to do this. Thirdly, if the student and his family are wrong, what are they observing that leads them to believe that the ants are long term weather changes?

    My class and I would greatly appreciate any insights you are able to offer on this topic.

    Kind regards,


    Dear Max,

    Thanks for your question!
    There are a variety of ways that human meteorologists can predict the weather: they can look at trends in barometric pressure, they can note the wind direction and look at the clouds (from the ground or from satellites). But they can also make general predictions based on past trends. I suspect that any meteorologist in your area could predict to the nearest 10 days when the first monsoon rains are likely to hit southeastern Queensland, and they wouldn't need any information at all about the current weather! In many areas of the world, there are predictable times of year that organisms need to prepare for or migrate away from--times of year that are either too cold, too hot, too wet, or too dry for organisms to function well. Some organisms whose ancestors have been living in those places for millions of years are adapted to the annual rhythm of these seasons. The ants your student and his family observed are not "predicting" the weather any more than migratory birds or blossoming flowers are--they're just behaving in a way that is adaptive to long periods of rainfall.

    Many animals and plants (and perhaps other organisms, like marine algae) have an instinctual response to seasonal cues like light levels or day length (photoperiod). For example, cherry trees from certain parts of Asia will always flower when days are as long as they are at the beginning of spring in that part of Asia. For other plant species, budding occurs only after some threshold of both photoperiod and temperature has been passed, and bird migration may be regulated by an even more complex interplay of cues, including food abundance. It has even been proposed that organisms might have "circannual clocks," the annual version of our circadian rhythms that get messed with when we travel to a new time zone. For many species, the exact cues used to regulate annual cycles of behavior and life history (or phenology) are not understood.

    I'm sure you've guessed by this point that I don't know exactly what cues the ants on your student's farm are responding to. But as a class, you might be able to perform some scientific experiments to figure it out! My understanding is that your rainy season is the Austral summer--the warmer time of the year, with longer days. Thus, two cues the ants might be using (separately or together) are the length of the days and the temperature. If there are many of these ant nests, then you could set up lights around some nests about half way through the winter, and put them on a timer so that they turned on a half hour before dawn and again a half hour after dark. Near other nests, you could place some "heat rocks," like those used for reptiles. Some nests could receive both treatments, and some nests neither. Then you could see if any of the ant nests "predict" that the rains will come earlier than others. Unfortunately, you might have to wait until next year to perform this experiment, but, hey, it doesn't hurt to plan ahead, right?

    One reason phenology and chronobiology are such "hot" topics lately is that global climate change is likely to make things difficult for organisms that use photoperiod as a cue to adjust to the changing of the seasons. Perhaps you and your class (or future classes) could help us better understand how the ants of Australia will react to climate change!

    Hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    Hi there!

    I've recently observed a bunch of ants on my desk at my lab that seem to "freeze" in movement, in a group, usually in a straight (but not linked) line against the wall, completely stationary for hours at a time. They're usually gone by morning and they tend to return again, usually in the afternoon and the cycle repeats. I've been trying to read up for info on this online but I haven't found any information that explains this. These are small brown ants, common to households, but I'm unsure as to the exact species.

    I apologise in advance for the lack of information but I'm extremely curious as to what causes this behavior.

    Hope you can shed some light on this.

    Thank you

    Dear Felicia

    The ants you saw are most likely Tetramorium bicarinatum, a species that occurs in houses world-wide. One of the other contributers has observed the "freezing" behavior in other ants, but we really don't know why they do this. It is possible they are responding to vibrations in the object they're standing on, and that freezing might make them less visible to predators. This is a behavior we really don't understand.

    Hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    Dear Ant Experts,

    I have a large colony of ants in my yard (or possibly many colonies) in Surprise, AZ. These ants are becoming a small problem because they love to bite my family. So far I have tried many "ant baits" and found that they ignore all of them except for amdro pellets which contain Hydramethylnon. Boiling water works great on them when I can locate their hills, but they always return. Any information on what kind of ants these are and how to eradicate them will be very appreciated! Thank you in advance!


    Thumbnail image for Thumbnail image for CRW_8103.jpg

    Dear JJ,

    I wish I had some encouraging news for you, but it's likely you have Solenopsis xyloni, a close relative of the Red Imported Fire Ant, Solenopsis invicta. You're already doing some of the most effective things: Amdro was developed specifically to target S. invicta (or RIFA, as it's sometimes called in the invasive species literature). It works best if you pour about 1/4 cup directly onto the mounds, and re-treat every 2-3 weeks. In general, poisoned baits usually kill at most about 90% of the colony, so re-treatment is essential. Boiling water, as you said, is also great when you can find the colonies. Just don't pour it over the Amdro! It doesn't work when wet!

    The problem is, unless you and your family live on a 1,000-acre ranch, miles away from town, surrounded by a moat and a flying-ant-proof fence, you'll always risk re-infestation from the surrounding area. Therefore, the only further advice I have is to get organized with your community. It might make sense to bring this problem up with your neighbors, at your children's schools, and any local organizations you're involved with. The "School of Ants" is a citizen-science project that would be a fantastic way to gather information about where other colonies of these ants occur in your area...and the students might even learn a thing or two about the biology and ecology of ants!

    One critical bit of information you can get from collaborating with the folks at "School of Ants," or other experts, is a positive identification of these specimens. Solenopsis invicta and Solenopsis xyloni are difficult to tell apart from pictures, but one is a native ant that can be a nuisance, and one is an invasive ant that costs the USA more six billion dollars a year to control nation-wide. More information on Solenopsis invicta, and some advice about distinguishing it from related species, can be found on this excellent site.
    Either way, you have the opportunity to raise awareness in your community about ants, so that you can more effectively solve the problem you have now, and be prepared for future ant invasions.

    Good luck!
    Jesse Czekanski-Moir & the AntAsk Team

    Thanks for your question, Nathalie!

    It is true that ants are proportionately much stronger than we are. I don't think any human could dangle from the ceiling with 100 times his or her body weight, like the weaver ant Oecophylla pictured here. There are many adaptations that are working together to allow ants to perform impressive feats like these: hairs on their feet that can stick to very smooth surfaces, large muscles in their heads to close their jaws, and light lean bodies. Most worker ants don't have functional reproductive systems, so their strength-to-weight ratios are higher than many other insects that are weighed down with the burden of perpetuating their genes.

    However, comparing the proportional strength of even the strongest humans to an ant is unfair. Even lions, tigers, and bears (oh my!) can't lift more than 10 times their own body weight, as many insects can. Some of the physics behind this is explained here. The strength of ants is "super," but it is not super-natural. It all makes sense once you know a little more about physics.

    Briefly, smaller organisms will always have bigger strength-to-weight ratios, because it's the surface area of the muscle cross section that determines strength, but the volume of the animal that (all else being equal) determines mass.

    Less briefly: imagine three perfect cubes, each of a different length: 2cm, 5cm, and 10cm. The 2cm cube has a cross-sectional area of 2x2=4cm^2 and a volume of 2x2x2=8cm^3. The 5cm cube has a cross-sectional area of 5x5=25, and volume of 5x5x5=125, and the 10cm cube has cross-sectional area of 10x10=100 and 10x10x10=1000. If these cubes were animals (admittedly, very strange ones), the 2cm cube could have a strength-to-weight ratio that was proportional to 4/8, while the 5cm animal's strength to weight ratio would be 25/125 = 1/5, and the largest, 10cm cube-animal would have a strength-to-weight ratio of 10/1000 = 1/100. Of course, this is an oversimplification, but I hope this helps clarify why all of the proportionately strongest animals are very small.

    Although this is an ant blog, I feel it is only fair to point out that ants are not the strongest insect, even proportionately to their body weight. The prize goes to a dung beetle, which can drag more than 1000 times its body weight. These beetles are larger than any ant, which makes their strength-to-weight ratio even more impressive.

    The feat of strength in which ants have beetles beat is how rapidly some of them can close their jaws. Ants of the genus Odontomachus can close their jaws at speeds of up to 230 km/hr (143mph), generating a force that is 500 times their body mass. Not only are these forces very effective at subduing prey and smaller enemies, some of them can use their jaws to launch themselves into the air. This youtube video is completely worth checking out if you like wathching slow-motion ants flail through the air. For a more dignified synopsis, one of the original articles on Odontomachus jaws is here.

    I hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    Hey everyone,

    I've always found ants to be one of the most fascinating creatures on this planet, and while I was walking on a path the other day, I found these red ants moving back and forth along the path transporting their eggs. Just wondering if anyone can identify it and if someone could direct me to way to identify ants in my area on my own, that would be fantastic. I'm located in Calgary, Alberta, Canada and that is where this photo was taken.


    DSC_3969.JPGView image

    Hi Steve,

    Thanks so much for the great photo. I have to warn you that what I'm about to say might be so fascinating that it will make your mind explode. These ants are transporting pupae (homologous to the "coccoon" stage that caterpillars go through before they become butterflies or moths), but there's a good chance that it's not their pupae. Members of the genus Formica are tricky to identify, but I'm willing to bet that this one you observed belongs to one of the species that actually "enslaves" or "domesticates" closely related species of ants (such as members of the sanguinea group, like Formica aserva). The workers run into a nearby colony, and forceably remove the silk-encased pupae from the other species. When these pupal ants emerge as adults, they think they are in their home colony, but are actually unwitting servants to anther species! For an interesting discussion on what exactly the common name of this behavior should be ("domestication", "slave-rading", "piracy", etc.) check out this post by Alex Wild and this post by frequent AntBlog contributor James Trager.

    Hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    at 11:30pm, 20 May 2012, Gerald wrote:
    This year at my home there are no ants in my yard, garden, nowhere
    In Cathedral City, Ca.
    Do you think we are going to have a big earth quake

    at 12:30pm, 21 May 2012, Jesse wrote:
    Dear Gerald,


    Just joking. Ants have not been shown to be able to predict earthquakes. During careful behavioral observations of the harvester ants Messor pergandei, John Lighton and Frances Duncan noted no change in activity before, during, or up to three days after a magnitude 7.4 earthquake in the Mojave desert in 1992 (they published the report in 2005 in the Journal of Experimental Biology - doi: 10.1242/​jeb.01735). The authors conclude that "anecdotal accounts of the effects of earthquakes or their precursors on insect behavior should be interpreted with caution."

    It is more likely that ant activity is very low because of recent weather patterns, or your town (or an overzealous neighbor) has used broadcast insecticides to get rid of some type of insect pest. You might consider contacting your town hall to see if there have been any recent applications of pesticides, for mosquitos, or a particular crop pest, for example.

    Hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    at 1:06pm 21 May 2012 Gerald wrote:
    Well this morning we had 3.7 in Kern county

    at 1:45pm 21 May 2012 Jesse wrote:
    Hey Gerald,

    That's interesting. It's possible that there were some different cues leading up to your earthquake that weren't present for the 1992 earthquake Lighton and Duncan observed. In the case of both your observations and theirs, this situation underscores the need for replication in science. In your case, I would caution that "correlation does not imply causation," and that without controlled experiments and/or a lot of careful observations, we can't come to any conclusions with respect to ants' ability to predict earthquakes. In the broader, philosophy of science scheme of things, you failed to falsify the hypothesis that ants can predict earthquakes, but Lighton and Duncan's observations falsified that hypothesis. Again, they're both one-time observations, but you or someone else would need to gather more data to cast Lighton and Duncan's findings in doubt.

    I'm sure you get quite a few earthquakes in your area, so it would be great to initiate some citizen science that involves ant monitoring. It would be a great way, for example, to get kids involved in science and natural history. If you were able to coordinate with some local summer camps, for example, you could gather quite a bit of useful data with respect to this very practical question, and give kids a taste of what it's like to do science that's important to their community.


    Greetings AntAsk!

    I must say, having Googled my way to your site while searching for possible identification of the new ants that have found their way in, I found myself going through many pages of archives and forgetting why I started reading your blog in the first place. But I do have an identification issue I'd like your two cents on, if you could. Picture attached (after trying two different cameras and about 30 minutes of fiddling with settings to finally get a shot that wasn't just a massive blur).

    I am in northeast Texas, and early last week we got hit by the mother of spring rains including damaging hail and some tornadoes. I also had our quarterly pest control visit 5 days ago. I think these guys got washed out or relocated by the weather, then further disrupted by the Orkin man. I noticed ants in our kitchen two days ago - though NOT by the food or the pets' water bowl not four feet away, just crawling along the baseboard by the backdoor. One quick Terro treatment and they were gone. This morning I found the same kind of ants on my bedroom windowsill.

    This time, though, they weren't marching anywhere. There are three relatively gigantic (half-dollar-sized) collections of them clinging to the wood and the wall along the corner of the windowsill and only a couple moving in through what I can only assume is a microscopic crack in the window. I have another Terro treatment down and have a call in to the Orkin man for a re-visit, but I kind of want to know what you think.

    My Google-assisted guess is that they're Argentine ants potentially out recolonizing/mating, but I'm very much a layman when it comes to mermecology, so that's just a stab in the dark from a curious mind. Two questions come to mind right now: 1) what are they, and 2) how much weatherproofing am I looking forward to in order to shore up any cracks in windows/doors/baseboards/etc.?

    Thanks in advance!

    Dallas, TX


    Dear Carissa,

    Thanks for the question. Unfortunately, some of these likely subjects are difficult to tell apart with out a microscope. There's a good chance they're the common Tapinoma sessile. One of our other experts, James Trager, writes: "I'd be willing to make a small bet they're Tapinoma sessile. Terro baits keep them at bay in my house (at my wife's insistence), without, I am glad to say, harming the numerous colonies around the yard that do not enter the house."

    It is difficult to rule out Linepithema humile, however. In general, T. sessile is more likely to be spotted inside a house. In the field, they actually can be distinguished by their odor if you pick them up and schmush them a little between your fingers, but this takes practice, and some familiarity with both. The difference in odor is difficult to describe (T. sessile has been described as being somewhere between 'coconut' and 'citronella').

    Regardless, the fact that they are attracted to terro baits is encouraging. No matter what the species, the trick is that one treatment is never enough. At most, you generally take out 80-90% of the ants, so they'll quickly bounce back if you don't keep applying. For the cost conscious, the terro-bait recipe can be pretty much replicated with sugar, water, and Borax by following these instructions (click here).

    Weatherproofing would probably help, but personally, I'd wait a little while to see how the bait was working.

    Hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team


    Are ant social parasites and host ants examples of sympatric speciation?



    Whew, this is quite the question!

    The short answer is: I don't know, but probably not.

    To give a longer and somewhat more complete answer (though still not one that might completely satisfy you) I'm going to back up a little bit and get our other readers up to speed on some of the different strategies ants use to exploit each other--the different flavors of nest parasitism. I also think it might be useful to define sympatric speciation.

    There are many species of ants, such as the members of the (Diploroptrum group within the genus Solenopsis, aka 'thief ants') that are thought to make their living from living very close to larger ant nests and stealing stored food and/or eggs and other brood. At the nest level, these ants are technically parasites (I've heard myrmecologists refer to them as kleptoparasites, although this term is usually reserved for organisms that steal food or other resources from other organisms, not baby-eaters). The exact behavioral ecology and the extent to which these relationships are specific is not known for many of these groups, but the hosts of thief ants tend to be larger ants from different genera, so it's unlikely that members of this variety of nest parasitism are examples of sympatric speciation.

    While "thief ants" tend to build their nests just on the outskirts of a host nest, there are other ants that actually live inside ant nests. Animals (ants and otherwise) that live in other social insect nests are said to be "inquiline." There are many kinds of arthropods and other organisms that have observed to be inquilines in different types of ant nests, and there are ants that are inquiline in termite nests (for example, members of the genus Metapone). Either case could, I suppose, be considered an "ant social parasite," but for the purposes of this blog post, I'll focus on ants that are inquiline within other ant nests. Much more detail about the many flavors of inquilinism can be found in this excellent review (Buschinger 2009), but rather than summarize that article, I'm going to emphasize that inquilines are the category of parasites that might be most promising group in which to look for examples of sympatric speciation. I will return to this idea (finally!) in just a few more paragraphs.

    Another parasitic strategy that some ants employ is stealing pupae from another nest, bringing them back to their own nests, and making those ants do all the work. These ants have sometimes been referred to as slave-raiders (see a great discussion here as to whether or not to refer to use this terminology); Polyergus is the textbook example. This genus is exclusively comprised of ants that steal pupae from members of the genus Formica. There are several species of Polyergus, but some of them seem to have non-overlapping geographic ranges. For example, Polyergus samurai is found in Japan, whereas other species are found in Mongolia, Northwestern Europe, or the American Southwest. These distinct geographic ranges suggest that allopatric speciation might be most likely mechanism of diversification in this genus, Although it is intriguing that they come out sister to their host ant, Formica, in the ant phylogeny by Moreau et al. (2006).

    Speaking of allopatric speciation: what is that? And what is sympatric speciation?

    Saying that speciation is allopatric is basically just saying that a pair of populations speciated because they were geographically isolated. Speciation is said to be sympatric if reproductive isolation occurs in populations whose ranges overlap substantially (it doesn't count if the populations speciate while they're separated and then later come back into contact, which can make distinguishing between these two modes tricky). The classic examples of sympatric speciation involve host shifts in parasites: if the ranges of the hosts overlap, and speciation occurs because of a host-shift, then many would argue that this is an example of sympatric speciation. Others would actually classify this as "micro-allopatric," because at small scales, the ranges of the new species never overlap, i.e., they're "never" on the same plant. I think this distinction is a little silly, though. To me, allopatric speciation implies the existence of a (usually geologic) barrier to dispersal between populations, like a river or a mountain range. To say populations are in allopatry because they are behaviorally inclined to eat different plants is just...silly. Stephen Stearns at Yale has a great lecture on speciation here if you want more depth on this somewhat daunting subject.

    Anyway, this definition suggests two intriguing ways in which sympatric speciation might be important for the diversification of ant social parasites: new species might arise in lineages that are already parasitic because of a host switch, and parasitism might arise within a population of non-parasitic ants. The former case is straightforward in principle: in order to better dominate/fool their hosts, parasitic ants need to adjust their smell (cuticular hydrocarbon profile), which is also important in mate recognition; thus, if you've been parasitizing different species, you might not recognize each other as mates. There are several species of ants that are known to parasitize a few different hosts, and these might be interesting candidates to look for cryptic, sympatric speciation within (cryptic species are genetically isolated, but difficult or impossible to tell apart under the microscope). I don't know of any documented examples of this speciation-by-host-shift mode, however, which may be due in part to how risky the nest-raiding lifestyle is. It may also be due to my incomplete knowledge of this subject, and the generally incomplete state of natural history and genetic knowledge of ants. In general, though, the inquiline lifestyle is risky, and host ants are patchily distributed across landscapes. Host specialization is a good strategy for herbivores with abundant food sources (whose only defenses are chemicals; plants won't try to bite your body in half), but if there are examples of speciation-by-host-switching in ants, I suspect those species would have a very high extinction probability, so at any given time they would be exceedingly rare.

    Sympatric speciation due to a shift from a free-living lifestyle to parasitizing your relatives is difficult to rule out. There are many instances of social insect parasites that seem to be closely related to their hosts (this pattern actually has a name: Emery's rule). There are numerous documented examples of intra-specific parasitism: newly mated queens attempting (and sometimes succeeding) in joining pre-existing colonies (so: intra-specific inquilines), and of same-species raids in which pupae are stolen and made to work in the new colony. It seems like a simple logical sequence to move from within-species parasitism to sister-species parasitism in a perfectly sympatric way. There is some unpublished evidence of multiple origins of inquilinism in the genus Tapinoma in North America, which is consistent with sympatric speciation, but these data are very preliminary, and cannot rule out allopatric speciation, as I'll discuss below.

    The difficulty I have with the sympatric scenario is that there is still no mechanism for reproductive isolation: what prevents the "parasites" from mating with the "hosts" if they haven't already speciated? To me, it seems more likely that Emery's rule arises from the fact that sister species are pre-adapted to foiling each other's nestmate recognition abilities. The smells ants use to recognize each other have a hereditary component, and so closely-related species are more likely to stumble upon the perfect disguise, as it were. My scenario requires that:
    1) Populations of a single species were isolated,
    2) These populations speciate allopatrically,
    3) They return to contact with one another, and
    4) One evolves the ability to exploit the other.

    This may seem like an unlikely scenario, but the first three stages are thought to have happened repeatedly in insect species, especially over the past few million years following the glaciation cycles in the northern hemisphere. (Siepielski et al. describe the ecological repercussions of this process in damselfly communities in the Northeastern United States here. A pattern that would be consistent with my scenario would be a higher proportion of close-relative parasitisms in areas that are thought to have undergone more recent, repeated range shifts and expansions, such as the Northern Eurasia and North America, and the continental islands of Indonesia, as opposed to areas that have been more stable, like the Amazon Rainforest and perhaps some of the Southern hemisphere temperate areas.

    To me, this seems like a more likely scenario than either the host-switching or the rise of parasitism scenarios discussed above (note that Buschinger 2009, linked above, definitely disagrees with me). Some evolutionary biologists believe that, in general, we should assume speciation has been allopatric unless there is compelling evidence otherwise (for a more full discussion, see a 2002 review of sypatric speciation by Berlocher and Feder here). While my scenario is essentially a "just so story," I think these scenarios are important to consider when evaluating the likelihood of different mechanisms in ecology and evolution.

    However, there are many areas of the world where new ants have been introduced, and it would be theoretically possible to catch a host-switch sympatric speciation event in action. Just as the most clear-cut example of sympatric speciation occurred during a host-switch from one plant to an introduced one (Rhagoletis flies switching from native hawthorn trees to introduced apple trees in North America), it might be very advantageous for inquiline ants in Europe or Japan to be able to exploit, say, the invasive Argentine ant (Linepithema humile). This might require a specialized smell disguise, which in turn could lead to a mutual lack of attraction between otherwise compatible mates.

    This and many other areas of social insect parasitism are completely fascinating to me, but these ants are so rare that much of our knowledge is very fragmentary. When you look for ants, keep your eyes out for inquilines, but don't be disappointed if you don't find any!

    I hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    To whom it my concern,

    Hi, I live around Ozark, Missouri, and heard that their were some nice orchids and morells in this little wooded patch across from the Walmart over by 65. Anyway, I wanted to try to photograph some of them with my new macro lens, when I saw these strange ants, I mean they just looked really wierd. I read a few of you're blog posts, and thought maybe they were those velvet ant things?

    Thanks a bunch!



    Dear Rick,

    These ants almost certainly belong to the genus Polyrhachis. There is a species that is fairly common in Southeast Asia that closely resembles the ants in your photographs, Polyrhachis bellicosa.

    It is very strange that these ants have ended up in Missouri. If it weren't for the date, and the fact that you have the same name as a one-hit-wonder from the 80s, I might ask you to take some voucher specimens. As it stands, I'll just advise you that being funny and being cool with the lines is actually not the way love is supposed to be. That's why my girl doesn't like you. You're shallow and narcissistic.

    Jesse Czekanski-Moir & the AntAsk Team

    Dear AntAsk,

    Last night my brother was stung by something that looked a lot like the Myrmecia piliventris. I didn't take a picture (I was too busy trying to kill it), but I found Alex Wild's photo on the internet, and the thing that bit my brother looked a lot like it.
    I read on Wikipedia that these ants are mostly found in Australia, and since we live in Namibia, I was wondering what it could be? Any idea?


    Dear Corien,

    Next time, kill the ant more carefully! (or better yet, photograph it alive, like Alex Wild would). Without specific information about which parts of the ant reminded you of Myrmecia, it's hard to say what species it was. One thing I'm fairly certain of is that it is not Myrmecia piliventris. Unless you or one of your neighbors just came back from a trip to Australia, it's pretty unlikely that genus would show up anywhere outside of Australia, or the islands immediately next to it (Myrmecia is also native to New Caledonia). Members that genus have been reported by New Zealand quarantine officers, though, so it's not impossible that commerce will one day introduce a "bulldog" ant to some place beyond the land down under.

    I'd say your best bet is to check our Ants of Kenya page. It's still not exactly Namibia, but the genera at least are much more likely to occur in both Kenya and Namibia than Australia and Namibia.

    If it was the mouthparts (mandibles) of Myrmecia that reminded you of the ant that stung your brother, then some possibilities that leap to mind are the genera Leptogenys and Plectroctena. Plectroctena can grow quite large (with a headwidth of 4mm). Leptogenys are generally smaller, and look as if they are probably faster. Although they do have pretty noticeable stings, it would have been difficult to see the mandibles on most Leptogenys species I'm aware of without using a microscope, so I doubt it's that one.

    Another noteworthy trait that Myrmecia has are their large eyes. In Africa, Asia, and Australia, the ants with some of the largest eyes relative to their head sizes belong to the genus Tetraponera. These ants (and their relatives in the Americas, Pseudomyrmex) have some of the largest eyes in the ant family, and their elongate bodies are similar in shape to the bodies of Myrmecia. While some Tetraponera can grow quite large and be rather aggressive, like the Southeast Asian Tetraponera rufonigra, I can't find evidence that there is a Tetraponera that big in West Africa.

    In many parts of the world, especially in the tropics, if a medium-large ant has just painfully stung you, there's a good chance it belongs to the genera Pachycondyla or Odontomachus. These don't bear a specific resemblance to Myrmecia (Odontomachus does have elongate mandibles, but they are attached near the midline of their faces, rather than at the corners as in Myrmecia, Plectroctena, and Leptogenys), but they might be more common in some places than other genera mentioned in this post.

    Good luck! Feel free to send us pictures if you see an ant like that again!
    Jesse Czekanski-Moir & the AntAsk Team

    Dear AntAsk,
    I live in Puerto Rico and am wondering about a tiny ant whose bite
    continues to burn after it bites and likes to eat cotton clothing. And
    scurries in and out of electronic equipment like my comptuer keyboard
    and my other electronic things like the dials on my electric guitar.
    They also like paper. and books - I see them outside where they like
    very dry wood and leaves - and digest dry wood as well. They look just
    like ants - act just like ants - How do I get rid of them as I can't
    spray my equipment. and my clothes.



    Dear Sonja,

    Thanks for contacting AntBlog. Chances are you have one of two species: Wasmannia auropunctata or Monomorium destructor. Wasmannia workers are all the exact same size and their bodies tend to be all the same color (they can be light or dark, but it's usually one or the other). Monomorium destructor are red-brown in the front part of their bodies, and darker in the back. Their workers are different sizes: within one foraging trail, you'll often see workers that are twice as big as the smallest ones, and there will be sizes between those two. Monomorium destructor has more of a tendancy to damage clothing (like you mentioned) and electrical equipment, but both species (and many others) will nest in a variety of small containers like electrical boxes and clothing drawers.

    In previous posts (click here, here, here ), we've outlined some general strategies for getting rid of ants using commercially availible poisons like Borax. I would add putting items in the freezer for 24 hours will often kill them in small electronic items (and anything else you can fit in the freezer).

    You also might want to check out the website of our friend, Cas Vanderwoude in Hawaii:
    He has some useful tips there for how to get rid of Wasmannia auropunctata, and the research his team is doing to fight this invasive species.

    Good luck! Sorry you're having so much trouble with these ants!
    Jesse Czekanski-Moir & the AntAsk Team

    Dear AntAsk,
    My name is Hadar and I live in Israel. I am the owner of the company for pest control in Israel that specializes in the extermination of ants using baits
    During the last five years we are dealing with the failure of eradication of the species Plagiolepis. We've tried most types of bait offered the U.S. pesticide market without success. Needless to say that spraying pesticides is not effective at all.
    We tried various baits containing borax or fipronil or abamectin B1 imidiachloropid.
    The baits contain honey dew or protein. Often appears in the attraction of that work and "workers" vigorously and after a while sometimes minutes, sometimes days after the placement of abandoned ant bait
    Can I get some information about the lifestyles of this ant? Such as:
    What kind of diet prefers this species?
    Is there more than one queen in the nest?
    How to deal with this pest
    This species is very common throughout the country from north to south
    Unfortunately, an Israeli research on this species is not done yet
    Please help

    Dear Hadar,

    Sorry to hear that you're having trouble with Plagiolepis. Although only a few species have been studied in depth, it seems that there is evidence of polygyny (multiple queens in the same colony) in every species in which this quality has been looked for ( P. pygmaea, P. xene, P. taurica, P. schmitzii, and P. maura - data and references in Thurin et al. 2011; DOI: 10.1111/j.1365-294X.2011.05161.x).

    As for what your Plagiolepis eats in the wild, it is likely that even if we did know what species you were working with, there would not be a complete, published study that would answer this question. What is more important is that you continue to experiment with baits to which this ant might be attracted that you can mix with the appropriate poisons. Invasive ant expert Cas Vanderwoude ( explains:

    We have Plagiolepis alluaudi here in Hawai`i. They seem fairly "skittish" and do not seem to feed on any particular food source. I think they are present in homes more for water than anything else.

    My standard approach would be to offer a buffet of food items that they might feed on, add a toxicant to the most attractive item and bait with that mixture. So Hadar, try a little (1)peanut butter, (2) jam or jelly, and (3) spam or tuna or fish flavored cat food. Also, try water. Put it in a vial filled with cotton wadding so the ants can "suck" the water from the wadding. You might be surprised - it might be water they recruit to most! If that's the case, thank my friend Evan Harris for that suggestion... if water and sugar are both attractive, you can make a nice attractant out of sugar water (25% sugar) and place it in the vials mentioned previously.

    Adding a toxicant is the next step. If you have fipronil it will be the most effective. The most important thing is the dose. DO NOT OVER-DOSE!!! For fipronil, use only 0.1g/kg bait mix - NO MORE! The effective range will be 0.01-0.1 g/kg active ingredient. Any more and it will take effect too soon and leave the queen(s) unaffected. Repeat baiting every 6-8 weeks."

    In addition to Cas's tips, I would add that it is important to apply poison at an effective spatial scale. If you're going to poison the ants in one person's house, but they live two meters away from a large colony, there is a very strong likelihood of re-infestation. Cas's point about re-applying baits is also very important; no treatment will kill 100% the first time. Often, treatments will kill around 90% of the ants at most, so it is important to keep re-applying the pesticide at the right time intervals. Ants do not eat while they are in their pupal stage (something like the cocoon a caterpillar makes before becoming a butterfly), so re-applying pesticides while the same ants are in their pupal stages will not increase the effectiveness of the treatment.

    For further information about dealing with invasive ants, I'd encourage you to check out Cas's website (above). For example, there is some information on treating potted plants for pests by submerging them in water at 45C which might be useful for some situations.

    I hope this helps!
    Jesse Czekanski-Moir, Cas Vanderwoude, and the AntAsk Team

    Dear Sirs,

    What looks like a flying ant appeared at the beginning of the rainy season, a few days ago, in great numbers, in Zanzibar

    They are not aggressive, no bite so far

    Could you tell me more about it?

    Many thanks and Kind regards


    Dear Anne,

    Thanks very much for your question! According our very own experts on Malagasy and East African ants, Brian Fisher, it's a queen Camponotus maculatus. The genus Camponotus occurs on all continents except Antarctica and is probably the second most diverse genus of ants (after Pheidole). Camponotus maculatus is widely distributed in East Africa, and forms that are either closely related, or within the same species also occur from the Middle East to insular Southeast Asia.

    Like many members of their genus, they probably nest in dead sections of living trees or vines. They are most likely generalist omnivores that will eat everything from nectar to dead insects. Camponotus are members of the ant subfamily Formicinae, and all of these ants have lost their stings and instead have the ability to spray formic acid. This is a very effective weapon against other insects and spiders, but unless it gets directly in your eyes or an open wound, you won't feel a thing.

    In the tropics and warm temperate deserts of the world, many ant species will have mating flights right after the first big rain of the rainy season. You may continue to see flying queens and males, but this will probably be the biggest swarm you see this year.

    I hope this helps!
    Jesse Czekanski-Moir & the AntAsk Team

    ps. for even more information on Camponotus, check out these other blog posts we've written that mention this cool ants!



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