Ants in your house or yard: August 2010 Archives


I have these ants in my kitchen in West Texas (Alpine). They appear
in the evening, have the run of the pantry, garbage, and countertops
and seem to disappear during the day. There used to be just a few but
now they are everywhere. They never get into food I can see - they
just do what the ant in the picture is doing, seemingly eating

What are they, and how do I get rid of them?

I appreciate your help.

Camponotus fragilis


Great picture, and great question! I think they look like Camponotus fragilis, a common species in the Southwestern US. As for some hints at how to get rid of them, we've outlined a general approach in a previous blog post (click here). If you decide to poison the ants, you might consider trying to do a quick "cafeteria" test to see what kind of bait you should mix with. Simply line up a few drops (liquid foods are preferable because you can mix them evenly with the poison) of different kinds of food on some wax paper, and see what the ants go for. I often try peanut butter, fake maple syrup, and pureed tuna fish (but perhaps see if they go for the peanut butter or maple syrup first, because pureed tuna fish can get kind of messy!).

But don't forget to try to figure out how they're getting in, and block off the entrance. If more ants keep getting inside, you won't be able to solve the problem with poisoned bait.

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

Dear AntAsk Team,

I live in southern New Mexico, (Las Cruces) and I have an odd little infestation of ants. Only in my bedroom, only in one little spot. I don't know how or where they are getting in, because they don't travel in a line. They are small and black. I did my own research, and can't decide if they are crazy ants or little black ants. Is one or the other more common here? How do I get rid of them? I honestly don't care if they are outside, since I can't find their nest anyways, but I don't want them in my room. I don't have a magnifying glass, so I can't see their nodes or antennae.

Please help me figure it out! Some are pretty tiny, but I'd say one out of five of them are significantly bigger, yet still small. I only ever get between 12 and 20 at a time, and only in one small spot in my bedroom. Can't find nests outside, can't find a line....But they are starting to take an interest in exploring my bed, and I am NOT ok with that, lol.

Thanks, Leah

Dear Leah,

Thanks for your question! Your observation that some workers are significantly bigger that others is very useful: there are some ants that have a worker caste that comes in two distinct sizes--we call those species dimorphic. Pheidole is a very common genus in many different habitats in North America that is dimorphic. Members of this genus are nicknamed "Big-Headed Ants," because the large worker caste have enormous heads. See for yourself!
Although it is glaringly obvious under a microscope, their big heads should be visible with the naked eye (if you look very closely, and if you have good eyes).

If the heads of the larger ants don't seem ridiculously huge, then it is likely that you have a member of the genus Monomorium. The members of this genus usually have workers that vary continuously in size, from large to small, but they usually travel slowly in distinct lines.

Crazy ants (this name usually refers to ants of the genus Paratrechina or Nylanderia) don't have workers of multiple sizes. However, if a worker drinks a lot of sugar water (or other sweet substance, or just plain water), the last section of their body (gaster) will become noticeably larger than other parts. So do your ants have big heads or big gasters?

Other common and very small, black ants include some members of the genera Solenopsis and Tapinoma, but these ants generally don't have works of different sizes.

As for how to get rid of ants in your room, we have some general tips in a different post, here. Please email us back if you don't have any luck, and we'll try and offer you some more advice.

Jesse Czekanski-Moir & the AntAsk Team

The ants we want to Identify are about 1/2" in length. We are in central Illinois.  They are living in an old pile of wood planks.  They are black, red, gray  (head, thorax, abdomen). Any help would be great. 
Jacksonville, Illinois


Thanks for your question! Although a picture would help to give you a positive identification, it is likely that you are looking at a member of the genus Camponotus. Members of this genus will typically be among the largest ants encountered in North America and Europe (and many other places; in Southeast Asia they have a truly giant species, see a previous post on giant ants ). These ants often live in rotting wood, including wood that has fallen, and rotten sections in living trees. Some species even live in rotting sections of people's houses! The ants commonly called "Carpenter Ants" belong to this genus, but the species in your area that lives up to this name, Camponotus pennsylvanicus is all black, so it's likely you're looking at a species that prefers the habitat in which you found it.

Based on your location and the description you gave, a likely candidate is Camponotus chromaiodes . But we encourage you to brows the Ants of Illinois page and the Ants of Missouri page to see if you can find a better match!

Hope this helps! You're welcome to send us pictures if you want a more positive identification, or if you have any further questions.

Jesse Czekanski-Moir & the AntAsk Team

Dear AntAsk Team,

I live in a suburb of Boston, MA and have noticed an increasing number of ants travelling through my garden. They seem to be going to a food source and bringing it back to their dwelling. Since they are clearly on a mission, I try to avoid stepping on them as I cross their path. All has been fine until today, when they began climbing onto my foot and biting me as I attemped to water the garden. I live in a zone with freezing temps in the winter, and an unusually hot spell this summer (with temps in the 80's and 90's daily). The ants are reddish-brown and no larger than a centimeter. There is a constant flow of them in both directions as they commute to and from their destination. I don't know where they nest nor where they go. How can I find out what type of ant they are and whether they are known to be an aggressive species? I have a "live and let live" philosophy, but I don't wish to get bitten when I go out the front door.


Good Evening,

I live in Reading Massachusetts and recently found some red/orange ants with a black gaster (back end) that run very fast around my lawn and walkways. I've had a few crawl on my leg and they haven't bitten me as of yet. This is the first time I've seen this and when my wife called the exterminator he said to spread some of the lawn granules and that should kill them.

I was wondering if you could help me identify them so I can figure out what they are and how to best treat and prevent them from taken over my yard and hopefully not my home. If not, can you help me with some other resources or companies that might be able to help me identify what type of ants they are?

Thank you for your help and support,

Dear gsonder and David,

It sounds like you might both be seeing the ant Formica exsectoides. Alexander Wild has some beautiful pictures of these ants that might be helpful in identification. A great book for help identifying ants in Massachusetts is Fisher and Cover's Ants of North America. You might also want to check out the ant section on the Massachusetts Audobon Society's website ( for some more information on your local ants.

Ants are generally great to have around the yard as they are an integral part of the ecosystem and can help clean up other dead organisms and plant debris. However, nobody wants them in their house or on their legs. For advice on keeping ants out of the house check out this post
As for the ants that bit you, it is certainly possible that the recent heat wave has increased their energy level and made them act more aggressively. Ants are not generally aggressive towards people so it was likely an isolated incident and if you avoid their foraging trails they will probably leave you alone. Unless they become a consistent or painful problem I would suggest leaving them to help clean up your yard.

Ben Rubin & the AntAsk Team

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