June 2012 Archives

I was vacuuming my house And when I got to my front entrance a had a swarm of these ants all over front door and walls...... It is quite a large ant approx a 1/4" long. I have heard that fire ant have been invading our area I have small pets and children so this was concerning to me.

I can get a better picture if needed

Michelle from Surrey BC, Canada.

Dear Michelle:

The photo lacks clarity, so we won't post it, but nonetheless I can assure you it is not a fire ant, and apparently is one of your native Formica or Lasius species (which have no sting).

Further, though we have had warming winters in recent years, the essentially tropical fire ants are still not established anywhere in or near Canada. The closest location to you is Orange Co., (far southern) California.

I hope this allays any fears for pets or children.

James C. Trager of the AntAsk Team


I have a two part Ant question that I am just so curious about.

We have a patio paved with stones and we have an Ant nest under it.We have seen the small reddish ants and their activity.

1. My question is are the Ants able to predict when it will rain? A day before rain comes we notice small sticks sticking out of the Ants nest holes.The sticks are in a very regular pattern,spaced about 6-10 inches apart.After the rain is gone for a day the sticks go away.

2. Is there more to plugging the holes beyond keeping rain out? Are they funneling water?

It is just so fascinating,we love watching wild creatures and their behaviors and when it's right out the back door, WoW!


Thank you so much for your time. We hope to hear from you soon,

Chance and Rois

Hi Chance and Rois,

Thanks for contacting us with these puzzling observations! I am not entirely sure about both your questions and here are some thoughts. As far as I know, it has never been scientifically proven that ants were able to predict rain, but there are many stories which claim it. There are also studies that claim that ants might even be able to predict earthquakes, because they sometimes nest on fault zones. It is hypothesized that ants detect Helium which is released before an earthquake.

Coming to your second question, I can only guess. I have never observed this behavior myself, but I've seen ants that cover their nests with rocks. This might be to prevent intruders from coming in or for keeping the rain out. In my own driveway, which has lots of cracks in the concrete because of tree roots, I also sometimes observe little sticks standing out. But we have little ants in the driveway and I think that earth worms are pulling the little sticks in to feed on them. They seem to chew them down. However, the sticks I see are much smaller and look softer than the one that you were showing. I found a picture online in which an earth work pulls a leaf into the ground to feed on it.

I think the only way to find out what is pulling the sticks in would be to dig it up. Let me know if you do so and what you find.


Here is a picture of an earthworm pulling in a leaf. (image taken from http://www.planet-wissen.de/alltag_gesundheit/landwirtschaft/wiese/wiesenaufbau.jsp)

I hope these thoughts help!

All the best,
Steffi Kautz & the AntAsk Team


I saw a picture of a leaf cutter ant and some other ants. The leaf cutter ant has a white circle (eye) on the center of its head. I noticed other ants have something there also but in different arrangements of three spots or the coloration is different. What is this? What is it for?



Hello Abigail,

The white circle you observed on the leaf cutter ant Atta cephalotes is a simple eye or ocellus. Ocelli occur in many other insect orders and function as auxiliary light sensory organs. Unlike the two main compound eyes, these simple eyes consist of a single ommatidium or "lens" and can perform only basic light/dark distinction. They are not typically found in the worker castes of most ant species but when they do occur, as in the genera Atta and Formica, they range in number from 1-3. The queens and males of all ant species always have 3 ocelli.

Thanks for your question,

Alexandra Westrich, Ben Rubin & the AntAsk Team

Hi all,

What is the biggest and the smallest species of ant? And where do they live?

Thanks, Cassio

Hi Cassio,

The biggest ants in the world are from the genus Dinoponera. The workers are about 3 cm in length (more than one inch). There are currently six valid species in the genus Dinoponera and they occur in Neotropical rainforests. The ant species Paraponera clavata, the giant Neotropical bullet ant, is also extremely large and the workers reach sizes of about an inch. Paraponera clavata also occurs in rainforests of the Neotropics and is distributed from Honduras in the North to Brazil in the South.

There are many very small ant species and the smallest probably belong to the genus Carebara. This genus comprises 160 valid species, which are found almost worldwide.

Dinoponera australis - one of the largest ants in the world. Photo from http://www.alexanderwild.com/

All the best,
Stefanie Kautz, Arista Tischner & the AntAsk Team

When in Borneo, I noticed that the Diacamma ponerines on the forest floor of primary forest surrounded the entrance to their nest at the bottom of saplings with nests of twigs like birds' nests. Do you know what these are for? They also turned out to be regularly spaced.


Ruth Levy


Hi Ruth,

The stacks of twigs over the entrances of the colonies you found are likely required for proper nest thermoregulation. Temperatures in ant nests must be maintained within particular limits or the ants may die or their young may fail to develop correctly. The twigs can contribute to temperature control by keeping nests out of direct sunlight and protecting against wind. We have several previous posts on colony temperature regulation here, here and here.

Thanks for your question,

Alexandra Westrich, Ben Rubin & the AntAsk Team


I have a general question about ant colony size:

Having secured their resources, why does an ant community choose expansion in size, structure and function? I guess that at a certain limit of population size things will start to get more difficult with every increase in contrast with a small population where more workers will make life easier and growth is a healthy thing.

Provided that resources are endless will an ant colony continue to grow or is there a target to be achieved? Will ants limit their population if food is scarce for example?

Grateful for your help,

Hello Ibrahim!

The size of an ant colony has to do both with the ant species and the availability of resources. With that said, it seems to be genetically determined how big an ant colony can get. Many ant colonies have only one egg-laying queen, while others have several and can reach larger colony sizes. Some species only reach colony sizes of a few hundred workers, whereas others can reach colony sizes of over a million, or several millions (for example leaf cutter ants). On the other hand, an entire ant colony of the genus Temnothorax can nest in a single acorn. However, when resources are scarce, an ant colony might not be able to expand to its full potential size.

Hope this helps,
Arista Tischner & the AntAsk Team

While hiking in a remote and Primitive forest in Lassen County of northern California I came across one very large ant.

All of the ants I had seen earlier that day were large and black. They were approximately 1/2 inch long and very stout. I hiked several more miles into a truly primitive and rustic area and found a black ant that was at least one inch long. I thought it must be some sort of queen but it was all alone. Any idea what it could be be. Could it be a carpenter ant? The trail is not far from the Pacific Rim trail which starts in San Diego and maybe this ant hitched a ride. I have looked everywhere and it seems that most ants in north America are under 1/2 inch.

I wish I had taken the poor fellow home. If the ant is unique then I will go back this summer and try and locate him and bring him back for research. If there is one, there is likely more ants.

Your advise is greatly appreciated,



Thank you for contacting AntBlog.

Unfortunately without a photograph it is difficult to say what ant species you observed, but from your description it is not out of the realm of possibilities that you found a queen of the larger ants (likely carpenter ants from the genus Camponotus) you saw earlier on your walk. Queens are often larger than workers and new founding queens can be exploring the local environment to find a suitable new home to start a colony.

You can see a list and photographs of the ants of California here.

Best regards,
Corrie Moreau & the AntAsk Team

hi--this morning we observed a lot of sidewalk ants swarming in our backyard (coming in/out of pavement cracks). there were winged ants (males?) flying up and dropping down periodically. some seemed to be struggling--flying around on their backs before righting themselves. now this evening there is no swarm, but some new piles of debris along some of the pavement cracks that a few ants are tending.

what was going on this morning? any help is appreciated!



Dear Virginia,

Although it is hard to identify the ants without pictures, it is quite possible that they are the common European pavement ant (Tetramorium caespitum), which have become one of the most abundant insects in the Northeastern US. If you want to try to identify them, follow this link to the AntWeb species page for Tetramorium caespitum.

As the winged ants are the reproductive members of the colony, it is possible that the colony you are observing was sending out queens and/or males to reproduce with other nearby colonies. Often, they form mating swarms with queens and males from many different colonies, so if the all the members of the swarm were winged, then it is likely that you were observing a mating swarm.

If there were only a few winged members in the swarm, then it is possible that you were observing a territorial battle between two different colonies of Tetramorium caespitum. These are fairly common on sidewalks and between pavement cracks, and have been documented well by the fantastic photographer Alex Wild. See the picture below for an example of these battles (Photo by Alex Wild).


I hope this answers your questions!


Max Winston & the AskAntTeam


I've always thought red and black ants were carpenter ants but I cannot find any picture of a carpenter ant that looks like these--and my land is crawling with them. We do have black carpenter ants on our porch (most unfortunately), and these are something else entirely.

Could you identify these for me? Is there anything I need to do to keep them in check within my ecosystem, and what natural controls would be optimal?

Thank you,


april 019.jpg


Hi Chaya,

Carpenter ant is the common name for ants in the genus Camponotus, but the ants on your land are wood ants in the genus Formica. We have a few previous posts that mention these ants here and here. Wood ants are native to North America and play an integral part in your local ecosystem by clearing away other insects and harvesting fallen pine needles for their nests. They are relatively harmless and do not normally require special control measures unless you find them to be excessively bothersome. They often change the location of their colonies so you may notice their numbers vary over time, even without any outside influence. Many wood ants can also construct large thatch mounds like the one shown here:

FormicaObscuripesNest-M.jpg Photograph courtesy of alexanderwild.com

Thanks for being concerned about your backyard ecosystem!

Ben Rubin, Alexandra Westrich & the AntAsk Team


I witnessed something that peeked my curiosity. I saw hundreds of ants moving in a straight line on a curb for about 50 yards. 1. Why would they do this? 2. 99% were moving in the same direction but occasionally one would fight the tide, why?


Hi Mark,

The behavior you witnessed could have been a colony moving to a new nest site. Parts of an ant colony or an entire colony move to a new nest if the previous has gotten too small or if resources around the nest have been exploited. It's also possible that the ants were performing a "raid", where they quickly swarm a food location. Did you happen to observe whether the ant workers were either carrying brood items or prey items? This might help to understand whether they were moving to a new nest site or were on a raid. The solitary ants moving against the tide were likely recruiting those which were still behind.

All the best,
Arista Tischner & the AntAsk Team

Hi, great blog. I've got a question for you if you might have the time...

Last week during the solar eclipse my family and I drove out past west Phoenix, AZ to get a clear view of the horizon - we ended up out in the dessert. I noticed a huge ant colony of large black ants about 1/4 inch in size, they were busy walking in lines in and out of their hole. I decided to collect about ten for an unused gel ant farm I have. I had the ants for a week and all but two of them just sat around in a group cleaning themselves, while two of the ants started digging tunnels. I figured I inadvertently collected mostly foraging worker ants. Now, one week later, this weekend I decided I would go back and try to capture ants that were bringing debris out of the hole, and avoid ants bringing thing into the hole, to try to get more digger ants. BUT! The ant hole was void of all activity, no ants. ... I trekked into the raw untamed dessert for about an hour and discovered many ant holes - not one ant the entire time! Figuring I was unlucky, I drove and explored a dirt road that took me deep into the dessert for about four miles, looking out for large ant holes along the way, and again, many holes but not one single ant! Is it an ant conspiracy? But seriously, I was scanning the ground for activity and not one ant the whole time?! Whats going on? This all took place in the afternoon to late day and the temperature reported 84 degrees on my iphone.

Thank you!


Glad to hear you are keeping ants! Ant farms can be a great way to observe and appreciate ants.

As for your observations about the missing ants it is possible that the original colony may have moved locations. Some ant species move their entire nests from time to time. Also, many ant species have ideal times of the day and temperatures to be active and it could be that you were there when the ants were deep in their nests for the evening.

Hopefully the ants will be back out and active the next time you venture out to the desert.

Best of luck,
Corrie Moreau & the AskAnt Team


I just found this little line of some LITTLE ants. The have distinctly black heads and clear-brown bodies. Very strange. I have some sugar ants in another part of the kitchen, but these new ants are smaller and definitely different. They seem to be attracted to water/liquids. They move in uniform lines, but they are wide lines. Help?

Tomball, TX


Dear Nicholas,

Without a picture, it is hard to say what species you have crawling around your house. However, by your description, it sounds like they could be Tapinoma melanocephalum. Follow the link to the AntWeb species page for Tapinoma melanocephalum to see whether your ants match our guess.

In terms of getting rid of the ants, check out this previous post for some good advice.

Hope this helps!


Max Winston & the AskAntTeam

The gender of ants

I'm interested in the fact that most ants are female and was wondering if you would know who first discovered the gender of ants and how this was discovered.
I'd love the name(s), years, or any info on how to find this information. Could you point me in that direction?
Thank you!

Susie Henderson

Excellent question, Susie. Just from memory, I was thinking the French Renaissance naturalist de RĂ©aumur first correctly interpreted the gender of ants back in the 1700s. But, to get more info, I posted this at an informal myrmecology forum frequented by a fellow who is very interested in the history of myrmecology. A quite thorough discussion of your question ensued. Turns out, I was right, but rather than repeat it all here: I will provide a link to that discussion - http://tinyurl.com/7fjczu9

Thanks for stimulating an interesting look into the history of ant science!

James C. Trager of the AskAnt Team.

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