AntWeb: March 2012 Archives


I have an old half buried patio next to my house that I plan to un-bury and relay the bricks. There seems to be a large ant colony that lives within these old bricks though. Last year, it was there as well, and in observing the ants, I noticed there were more than one species present (not living peacefully but rather keeping one another in check, perhaps?) Obviously I don't want to have a patio where there are several ants, but I was wondering if there is a way to get the ants to move the colony without getting rid of them? The yard seems to have a good level of checks and balance of living things, and I don't want to disturb that balance.

Any help is much appreciated.

Thank you



Hi Jackie,

The ants visible in your pictures are probably Formica subsericea. These ants sometimes host so-called slave-making ants, caring for their dominant partners without having a queen of their own. It is possible that the Formica subsericea ants you have seen are living as slaves of another species, explaining the presence of other types of ants. If this was the case they would act peacefully towards each other as they are members of the same colony.

Moving a colony without destroying it is very difficult. However, many ants regularly relocate their nests on their own, and it turns out that this behavior has been previously studied in Formica subsericea (Smallwood 1982 - full citation below). According to Smallwood (1982), Formica subsericea change nest sites about every 90 days. So if you wait long enough, they may leave on their own, though they could be replaced by yet another colony. Ho¨lldobler and Wilson have a section on ant nest relocation on page 171 of their 1990 book, "The Ants". They discuss a number of factors that are known to motivate some ants to relocate their nests including mechanical nest disturbance, flooding, competition, and predation. I doubt you want to prey on these ants but, given enough disturbance, they may choose to leave on their own. Digging up your old patio may be all the motivation the ants need to leave.

Thanks for your question and good luck with your patio,
Ben Rubin, James Trager, & the AntAsk Team

Smallwood J (1982) Nest relocation in ants. Insectes Sociaux 29:138-147.

Dear AntAsk,

I was wondering if the species Prenolepis imparis is up north in Ontario, Canada? I live about a half an hour away from London. And is this ant a queen and what is the species? Because if she's a queen it would be good to know if she was semi-claustral. So I can start feeding her and studying her species. And if she isn't a queen what are ants doing out early. Or is it common for ants up north to be out in March besides Prenolepis imparis? And thanks!


Dear Jacob,

According to this website, Prenolepis imparis is present in southern Ontario but the ant you found is a major worker of Camponotus pennsylvanicus. It is not unusual to see ants out in March if the weather has been mild. Check out this post and this post on what ants do in the winter and this post for a brief discussion of ant castes.

Thanks for your question,
James Trager, Ben Rubin, & the AntAsk Team

I live in Canada I was just wondering is there an ant species that
evolved just in Canada. Like just native here that would be pretty cool
like a Canadian ant that just evolved here then moved south? And what
is the most rare ant species in Canada? And are there ants in Antartica?
Thanks in advance - Jacob

Thanks for an excellent question, Jacob. There are a number of ant
species that were first discovered in Canada, and even some which have
the species name canadensis, the Latin word for Canadian. But
apparently, there are none found only in Canada. All Canadian species
may be found in American states on the Canadian border, or even farther
south, especially in the Rocky Mountains.

There are no ants in either the high Arctic (north of 67 deg. N), nor in
Antarctica. By contrast, in equatorial countries of South America,
Africa, or Asia, there are thousands of species. In non-Arctic North
America, the number is in between, about 900 species.

James Trager & the AntAsk Team