What to do when Terro doesn't work?

August 4, 2022 12:06 PM

In the past, I've always been able to make quick work of an ant infestation by putting down one trap, maybe two, they swarm it for a few days and then are never to be seen or heard from again.

This time, I've got ants in my bathroom that primarily seem to be attracted to the water in my sink and shower and seem to move faster than ants I've observed before. I put down a Terro trap, they swarmed it for a few days and disappeared. I removed the trap and then a few days later, they start appearing again. So I did another round of traps. Now, a few days later, they are back. So is it possible these traps aren't actually poisoning them or am I just dealing with an absolutely gigantic colony? Any other suggestions for things to try?

posted by Forty-eight to Home & Garden (10 answers total)

I find that I need to leave the Terro traps out for a couple of weeks to catch each wave of hatching ants that appear. Leave the traps out for maybe a month until you haven’t seen any more ants and you can probably safely call it done.
posted by corey flood at 12:13 PM on August 4, 2022 [4 favorites]

Tiny bathroom ants are very persistent. I think their colonies are quite extensive, yes.
posted by nouvelle-personne at 12:20 PM on August 4, 2022

Have you tried using the outdoor Terro traps? That seems to work best for me when I've got a ton of ants.
posted by dawkins_7 at 12:33 PM on August 4, 2022

if the terro traps are getting too expensive, you can make your own by mixing syrup (of any kind) or honey and regular laundry borax in a 3 to 1 ratio by volume. place on a coated cardboard square (like the printed side of a cereal box).
posted by ArgentCorvid at 12:49 PM on August 4, 2022 [4 favorites]

I do the boric acid + syrup thing and I find that it works pretty well assuming you don't have pets. You can just keep topping them off and it's a lot less expensive. Yes, it's possible there's just a large colony and/or favorable weather that are bringing them indoors.
posted by jessamyn at 1:04 PM on August 4, 2022 [1 favorite]

I've had success with Terro traps and liquid in the past but not recently. The Argentine ants were reliably attracted to sweet things but these new, smaller ants seem more interested in the savory, like grease and oil, and are just ignoring the Terro. Must I call in a professional?
posted by Rash at 2:16 PM on August 4, 2022

I sometimes find that I need to switch from Terro to a different product intermittently, when it seems like whatever ant wave I am dealing with is not interested in the Terro. I have been using these as the "alternative" product and they seem to do well when Terro isn't working. I think some ants prefer to eat different baits.
posted by Mid at 2:20 PM on August 4, 2022 [2 favorites]

Advion.
posted by ivanthenotsoterrible at 2:42 PM on August 4, 2022 [1 favorite]

Is being thirsty (as opposed to hungry) a thing with ants? I experienced something similar a few summers ago, and that's how I interpreted their behavior at the time. They went straight for the sink and ignored the bait. I ended up putting tape on the holes they were using to crawl into the sink and they lost interest.
posted by panic at 10:57 PM on August 4, 2022

When Terro doesn't work, I use abamectin poison dispensers (and vice-versa). The combination of the two has never failed me yet.
posted by Juffo-Wup at 5:29 PM on August 5, 2022