I live in Santa Fe, NM, and am trying to cope with an ant infestation. I've attached photos including a millimeter ruler so you can see what they look like. They go after food mostly. They loved the inside of the dishwasher when there were dirty dishes there - until I put ant powder under the dishwasher behind the toe kick plate. We've been fighting them for months. We started with ant traps, but they don't seem very interested in them any more. Ant powder is very effective, but as we have a little dog we must be very careful where we use it. We recently found a nest behind a radiant heating panel at the bottom of a paneled wall (indoors). I'm pretty sure there are multiple colonies by now. Any suggestions will be most welcome.
These ants are Tapinoma sessile, ID courtesy of Dr. James Trager. Commonly known as "odorous house ants" or simply "stink ants", this species is widespread across North America and frequently invades homes and other buildings for easy access to both food and favorable nesting sites. They actively colonize near heat sources or in insulation for effective brood-rearing, which explains their affinity for electrical appliances like dishwashers and radiant heat panels in your own home. They are largely harmless as house pests go, but if they become too much of a nuisance, there are a number of comprehensive steps to follow beyond laying traps and applying commercial ant killers. The following post addresses domestic ant control measures in fairly exhaustive detail, but you can also refer to other tips for containing ant infestations here and here. If you want to learn more about this species and see some stunning up-close photographs, check out this post by insect blogger and fellow myrmecologist Alex Wild.
Hope this helps,
Alexandra Westrich & the AntAsk Team