October 2011 Archives

Larval development


I have a question i hope you can answer for me.

I have recently started my own ant colony which is currently thriving. The ants have even created a new nest which is full of larvae at various stages of development.

I may need to provide a bigger habitat for them in future judging by how many larvae there seems to be in the new nest. However im not sure how long it takes the for an ant to go from a new layed larvae to an ant thats ready to go.
Could you give me some idea of the timeline for this?

The ant species i have is Polyrhachis Australis.
Any information you can provide me with would be grately appreciated.

Regards, Michael

Hello Michael:

Congratulations on your thriving Polyrhachis australis colony.

The question of how long it takes an ant to develop from egg to adult has been studied in only a relative few of the 14000 or so known kinds of ants. Most of the ones studied are those which infest buildings or are agricultural pests. Two house infesting ants, the Pharaoh ant Monomorium pharaonis and the ghost ant Tapinoma melanocephalum develop quite quickly, about three weeks from the laying of an egg by the queen to an adult worker, while fire ants Solenopsis invicta take about a month from egg to adult. On the other hand, some Myrmica species from the cold north of Siberia and Canada may take about two years to complete their development.

Unfortunately, your Polyrhachis australis fall into the category of ants whose development has not been studied. But I would estimate, based on my experience with related ants, that they complete their development in 8-12 weeks, in part depending on temperature. In other words, you might want to prepare for the rapid expansion of your colony with additional nesting space, sooner than later.

James C. Trager & 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 (https://www.littlefireants.com) 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

I was in Corcovado National Park in Costa Rica where I took this photo (sorry about the quality) of what I think is Camponotus sericeiventris. As you can see, the ant is walking over a sticky, black substance with no apparent problem. The whole trunk of the tree was covered in this substance - is it anything to do with the ants?

Many thanks

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Thank you for contacting AntBlog and including an image. We contacted an expert on the ants of Costa Rica, Dr. John T. Longino, to address your question. Here is what Dr. Longino had to say:

"Your ant is indeed Camponotus sericeiventris. I've often seen tree trunks with black, sticky, oozy areas, and ants often seem to be attracted to them. I have always surmised that these are tree infections, a result of wounds and/or pathogens, and that the tree sap is oozing out and evaporating, making a sweet exudate that ants might like. I doubt that the ants are the cause of the exudate.

From the look of your image, the area looks wet but not super sticky. Ants have no problem walking over wet surfaces. Also, if a sticky surface gets a "skin" of moisture or dryness, that would make it easy for an insect to walk over. We might touch a surface and break that thin surface layer, contacting the sticky material below. So a surface that seems sticky to us might not be to an insect.

By the way, I did my graduate work in Corcovado, back in early 1980's, and developed my love of ants there."

John "Jack" Longino (guest expert), Corrie Moreau & the AntAsk Team

I want to make an ant farm from a small aquarium I bought, but I need an ant queen. I don't want to dig up an existing colony. Would having a queen overpopulate the colony? How would I find a queen after its mating flight? I live in Arizona and it's October. I've heard that you need to look for a small hole with a small pile of dirt by it. I haven't seen any. Will ants make a larvae turn into a queen if there is no queen present like bees do? What time is mating season for ants in Arizona? Should I wait until mating season starts? -Austin

Hi Austin!

Thanks for contacting us! Digging up a colony to find the queen can sometimes be very hard. Often, the queen is hidden very deep in the soil and you might not find her. It might be easier to wait until next season for a newly mated queen.

James Trager has shared his expertise on the times when to expect newly mated queens of some ant species that are encountered in Arizona and are fun to keep in a formicarium. Here is his advice:

"Pogonomyrmex and Myrmecocystus flights are tied to rains, either monsoon, or spring, depending on the species.

Higher altitude, forest species of Camponotus fly on the first really warm days of spring, typically in April, May. Lower altitude species of oak-conifer woodlands, mesquite scrubland and true desert mostly fly with the first monsoon rains.

Finally, Formica species fly in July, especially early in the month, except the really high altitude ones, which may wait till August."

Here you can find more information on the ants of Arizona.

A queen would not overpopulate a colony. It is usually a good idea to have a queen, so that your ant colony lives past two month. The workers often die after this short time period and a queen would always supply new workers. Some of the larvae will turn into new queens, but they need to mate before they can lay fertilized eggs. It is very hard and often impossible to have ants mate in captivity. So it is best to find a freshly mated queen. You should keep your eyes open for several winged ant queens and keep one individual each in a small container. If one starts laying eggs, you can carefully transfer her to the bigger aquarium.

Here , here , and here are some other posts that might be helpful for you.

Good luck with your ant farm!

James Trager, Steffi Kautz & 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!


I would like to know if there is any sense to make out of the strange behavior I witnessed an ant making in my house.

I live in Long Island, NY and I guess the type of ant was a regular black carpenter ant. The first thing that struck me odd was that it had a very narrow thorax, almost like it was pinched in...But that might be 100% normal and I've just never looked that hard at an ant before.

The second thing that struck me odd was that it was standing still and seemed to be jittering its legs while they were planted on the floor, almost like wobbling them. I thought maybe it was neurological damage? Poison? I don't know.

I decided to get some cookie crumbs and a plastic cup so I can try to feed it and observe it for a little while. It did eat a bit which made me feel better. The next strange behavior I saw was that it started grooming the hell out of itself, almost manically as if it was on speed, then it proceed to bite at the bottom tip of it's abdomen. It was freaky; I thought maybe it was pregnant and ready to pop out some eggs or something. I don't think it was, though. It was really weird. I hope he wasn't sick or poisoned. I named him Mercury. I got grossed out from lying on the kitchen floor to watch all this and let it go off into the sunset...


Cheryl Cusimano


Hi Cheryl,

The ant you found was very likely a carpenter ant, but without a more thorough description or any photographic cues, this might be hard to confirm. The "narrow thorax" you observed could have been either the petiole of an ant (the small segment joining the mesosoma and gaster that gives all ants and many other hymenopterans the appearance of having a "waist") or the constricted petiolar segment of a parasitoid wasp. Ensign wasps (family Evaniidae), for example, superficially resemble black carpenter ants and are familiar (if less common) interlopers in domestic settings given their predatory association with cockroaches.

The jittering movement is likewise difficult to explain without further observation. If the insect was indeed an ensign wasp, you might compare this behavior with descriptions of the wasp's peculiar bobbing movements, which involve jerking its abdomen up and down like a hatchet.

The meticulous grooming behavior you observed is characteristic of almost all insects, especially after a meal. Whether this particular individual was an ant or a wasp, obsessive self-grooming would not be unexpected following close inspection of foreign objects like cookie crumbs or plastic cups.

Hope this helps,

Alexandra Westrich & the AntAsk Team

Hi there!

I'm curious as to what you guys feed your captive Odontomachus colonies. I feed mine mealworms because they're readily available, but they'll only accept it if I put the mealworm directly in the nest or at the nest entrance. Also, is it required to feed them sugary foods?

Another question, have any of you had experience with keeping Camponotus in plaster nests? I've heard that they're able to chew through plaster, has that ever happen to your Camponotus colonies? Thanks!



Thanks so much for the question, Phira. Odontomachus (sometimes called trap-jaw ants) are one of the coolest ants around. One of the experts on this group, Dr. Andy Suarez from the University of Illinois, gives this advice:

"We find that trap jaw ants are most excited about termites but will live happily on crickets and mealworms. Because crickets and mealworms are often infested with mites (because of the high densities that they are reared in at pet stores), we freeze them for a week or two before feeding them to the ants. We also tend to cut them up so the ants can get a bit of hemolymph. In addition to insects for protein, we try to always give trap jaw ants some sugar water or honey water. It is easily provided by making a 20% solution and then soaking a cotton ball in it. The cotton balls can them be removed if they start to mold."
In my own experience, Odontomachus in the wild will recruit to peanut butter baits (O. simillimus in Palau, and O. bauri in Panama). If you want to get more elaborate about ant colony nutrition, A. Dussutour and S. J. Simpson published an article in 2008 formally describing a precisely adjustable diet for ants mixing different protein powders, sugar, and agar. I used one version of that diet as an ant bait in Panama, and found many different ants were attracted to it.

With respect to sugar water, it is important because adult ants actually cannot swallow solid food. That's why you'll never see ants consuming solid food outside of their nest. They have to cut it up into manageable peices and bring it back to the larvae in the nest. The larvae chew and swallow the food, and regurgitate some of it for their adult sisters. So for small ant colonies which might not have many larvae at certain points, liquid foods are very important for the health of the adults.

As for Camponotus and plaster, I actually don't have any experience with that, but it seems like an easy hypothesis to test! Newly mated queens can certainly chew through fabric screening that can contain most other ants. They don't seem to be able to chew through metal screening however. If you like the way plaster regulates humidity, it might be worth trying to reinforce it with some metal screening.

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

Dear Ant Experts,

My lab partner and I designed a foraging experiment for our biology class to determine whether ants (Tetramorium caespitum) have a tendency to follow an established pheromone trail, or find a new food source. Can you provide insight on how to improve our methods?

We used a T-shaped apparatus constructed from PVC pipe with an opening at each end (three openings total). The PVC pipe was cut, allowing an aerial view of the ants when run through . Each arm of the T-shaped apparatus was approximately 6in in length. Food was placed at one opening of a T-shaped maze on aluminum foil. This food consisted of .25 mL of a 5% sugar water solution.A hole was cut into a 3x5 container and attached to the stem T-shaped apparatus. Then substrate from the excavation site, filled half of this container, and an ant was transferred using forceps from the 8x10-holding terrarium to the 3x5 container, which is attached to the maze. This provided a "home base" that ants would return to after food had been discovered. As well the stem of the T-shaped apparatus was lined with substrate. Once placed in the 3x5 container attached to the maze, the ant was allowed to scavenge for the food.Ten ants were run through the maze, separately to establish a trail to a food source.Then, the food source was then switched to the other end of the T-shaped maze. After the trail was established we would run 5 trials of 10 ants each. We would observe whether the ant followed the established path, or choose the path that led to food. Our hypothesis is that ants will always follow the established pheromone trail as long as it is potent and has not dissapated and it will take the proceeding ants less time to arrive at the end where the food originally presided then the first ant.

We ran into some difficulties, when we ran the first 10 ants to establish the pheromone trail. When we were running the ants through the t-shaped apparatus during the trial, they would be reluctant to leave home base, once they did leave home base and got pass the stem of the T-shaped apparatus lined with dirt, it took a substantial amount of time for them to forage around bifurcation. Only one ant that we ran actually arrived at the food, but did not return to the home base, before our class period ended. Other ants that we ran either returned to the home base prematurely (before food was found), or would walk around the food and not acknowledge it was there by eating from it or taking it back to the home base. Do ants need to eat or touch the food to acknowledge that it is there? We had first used grape jelly as a food source but it proved to be too sticky and viscous, because our ants drowned in the jelly. So we changed to a 10% sugar solution, but the ants would drag their appendages in the sugar solution ( while walking around the food) and then they would essentially be crippled, and have difficulty moving. Once they had dragged their appendages in the sugar solution they would try to return to the home base. This is why we diluted the solution to 5%, but the ants run through the T-shaped apparatus would not acknowledge this food source as well. Is there a more appealing food source we could use? Does the species Tetramorium caespitum release multiple pheromones for foraging such a repellent pheromone? How long does is take for the pheromone trail of Tetramorium caespitum to decay? How can we improve our methods, so that we can ensure results which our due in two weeks?


Hi Sandra,

Thanks for your e-mail and the very detailed description of your science project. The problem might be that the ants don't lay pheromone trails. Would it be possible for you to run the experiment for a much longer time and give the ants 1 hour to find the food source and release pheromones? Maybe that would help. Does the PVC tube itself smell, which might confuse the ants?

We have written a previous post here and here that might give you some ideas on baiting experiments. Alternative baits that the ants might work better: smaller drops of sugar solution (I suggest 20%), diluted honey, tuna, ham, dead insects.

Would it be possible that you re-design your experiment and tackle a different question? You could offer different baits simultaneously and test what the ants prefer. Read this post here and here to get some ideas.

The trail pheromone of Tetramorium caespitum has been identified and consists of two components. For the details, click on this link here.

Trail pheromones often decay pretty quickly, within about 10 minutes.

I hope this helps!
Steffi Kautz & the AntAsk Team

I heard of a study wherein ants were sprayed with a chemical that dead ants usually gave off and their nest-mates carried them off as if they were still dead even though they were still alive. Have you heard of this study and if so do you know where I can find it?


Hi Jon,

Thanks for your great question! The story is true. Researchers can capture the smell of a dead ant (or any insect) by dipping it in organic solvents (usually hexane) for a couple of minutes. The solvent can then be applied to another object or individual. The ants perceive this experimentally treated object or individual as dead and dispose it to the colony's dump sites. This behavior makes a lot of sense, because a dead and rotting individual would present a threat to the colony as disease could spread easily.

There are some great studies on this behavior (called necrophoresis):

Blum MS (1970) The Chemical Basis of Insect Sociality. In: Beroza M, editor. Chemicals Controlling Insect Behavior. New York: Academic; pp. 61-94.

Choe DW, Millar JG, Rust MK (2009) Chemical signals associated with life inhibit necrophoresis in Argentine ants. PNAS 106:8251-8255.

Gordon DH (1983) Dependence of necrophoric response to oleic acid on social context in the ant, Pogonomyrmex badius. J Chem Ecol. 9:105-111.

Haskins CP, Haskins EF (1974) Notes on necrophoric behavior in the archaic ant Myrmecia vindex (Formicidae: Myrmeciinae) Psyche 81:258-267.

Howard DF, Tschinkel WR (1976) Aspects of necrophoric behavior in the red imported fire ant, Solenopsis invicta. Behaviour 56:157-180.

Visscher PK (1983) The honey bee way of death: Necrophoric behaviour in Apis mellifera colonies. Anim Behav. 31:1070-1076.

Wilson EO, Durlach NI, Roth LM (1958) Chemical releasers of necrophoric behavior in ants. Psyche 65:108-114.

All the best,
Steffi Kautz & the AntAsk Team

Science Project (Sam, Utah)

Dear Ant Ask Team,

I am a fifth grader at Cherry Hill Elementary in Utah. I need an ant expert to answer some questions about ants for a school project. If you have time, will you be able to answer the following questions?

How do ants detect food, even if it's far away?
How do ants smell and how far can they?
What do ants like to eat?
Do the ants' antennae help them detect food?
What are the differences between ants with different jobs in a colony in reference to finding food?
Thanks for your help,



Dear Sam,

These are some very interesting questions! Although the answers vary depending on which of the more than 12,000 described species of ant we're talking about, here are some general answers to get you started:

1) Most often ants use the power of social cooperation to find food that's far away. Because they cannot "smell" the food in large distances away from the nest, they send "patroller" ants out of the nest to find food and then tell the rest of the colony where it is. As more and more ants find the source of food, they leave pheromone trails (see Iain Couzin's website for a really cool video of this) behind, which other ants can easily detect and follow to the food. Pretty cool!

2) Of course, it depends on factors like wind, or what they're smelling, but one study found that 6 cm was the maximum distance a harvester ant could respond to an alarm pheromone in still air. For Weaver ants (here's a cool article about their social behavior), that distance was more like 10 cm.

Here is a previous post with a more detailed response about how ants use chemicals called "pheromones" to communicate.

3) This is a tough one! Ants eat a wide variety of food, and have a number of interesting ways of getting it. For most ants, the most digestible food is probably sugar water, and so this is often what they are fed in a lab. In fact, leafcutter ants like this sugar water so much, that they actually use a specific fungi to digest leafs in the forest for them, and then eat the sugar water that the fungus produces! Just like miniature farmers.

4) Yes. The antennae help the ants follow trails of pheromones to get to food, as well as help the ants distinguish the food once they get there.

5) The Gordon Lab does a lot of work on the jobs of ants and how they change over time. Here is an interesting video that might give you a better idea of this:


I hope these answers help you with your Science project!

Max Winston & the AntAsk Team

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