Getting rid of anthills

Asked June 26, 2014, 2:43 PM EDT

We have several anthills near the house, some in flower beds where there are perennials I don't want to kill (e.g. with boiling water). There are tiny black ants, small black ants,(which bite) and large "carpenter" ants... those 3 kinds come into the kitchen.. What's effective for getting rid of them? Digging the whole hill out and pouring boiling water and vinegar on them didn't work -- they industriously rebuilt, and bit me the whole time I worked.

Erie County Ohio

3 Responses

If the stings left a little pustule behind, those were fire ants (they are the only ants that will leave that minimum reaction). Since they are above ground mounds, that sounds like fire ants as well. Other ants will make mounds, but fire ants are the most common ones to do so.
If its around a flower garden, just use any fire ant bait you can find at the nursery or hardware store. If you aren't sure they are fire ants, use a product called Amdro Ant Block, which has more than just fire ants on the label.
If they mounds are around a veggie bed, either use the bait outside of the bed, or use Conserve with Spinosad (which is labeled for use in a veggie garden).

The carpenter ants are another story - they won't be affected by those baits and can be difficult to manage. You have to find their nest and treat that direction. They don't make mounds, but will nest in dead wood (tree trunk, stump, door frame, window frame). When found inside, they may be making a satellite nest, and that is usually an indication of wet wood, which is a conducive condition for them. Make sure you don't have a leak or damage frames. You may end up needing to call a pest management professional if you want to get rid of them.

Molly, Thank you for the very helpful reply. We don't have mounds;I may have misled you by saying "anthills." The tops of nests are just slightly above ground level. We are in northern Ohio... are there fire ants here? I'll look for the Amdro Ant Block. In the house I use Terro bait, which is boric acid; all sizes of the ants eagerly eat it and after a few days they are gone, but sooner or later they are back.

I'm actually not really sure if you guys have fire ants Ohio - and I'm sorry for not catching that in the first email.
Since I'm not real familiar with what species of ants you guys have up there, you may want to get in touch with your local extension entomologist or an urban entomologist at Ohio State (they have a great entomology program).