I have a problem with ants in one of my garage walls. The bottom 8" of this wall is the typical big gray construction brick; above that is an insulated stud wall, with drywall on the interior. I never see any ants; what I see instead is their mine tailings that trickle out from the bottom of the drywall and accumulate on the garage floor. So apparently they are excavating the dirt inside the bricks and then dropping it over the edge of the brick into my garage.
A couple of years ago I had a professional pest control stop by. He had me drill into each stud space, and then he squirted in some pesticide powder. Problem solved - no sign of ants for a couple of years, until this summer. They’re back.
I gather the powder he used is only sold to licensed pest control professionals. So what can I buy myself to deal with this? Is there some other powder that’s less tightly regulated that I can get my hands on? any pesticide has to be delivered through small holes in the drywall into each stud space, so anything liquid is going to make a mess (and possibly damage the drywall).
Get borax and sugar. Put a mix of either 3:1 powdered sugar and borax into little containers or 1 cup water, 1/2 cup sugar, 3 tablespoons borax soaked into cotton balls where the ants can get to it, and let them eat it. They should be gone in a week or so. The sugar acts as bait so that they take it back to the nest, and the borax kills them once they eat it.
Borax. You can buy commercial preps which are just borax, some come with a sweetener. As described above they carry it back to the next where it eventually kills all the ants. You can also use a squeeze bottle to blow it into cracks.
You can buy professional strength stuff – you just can’t get it at the local hardware store. Here you go: Delta Dust + Bellow Duster
You don’t have to buy that particular duster but you do need a duster to use this stuff. That’s what I used to get rid of the carpenter bees that were destroying my carport and shed.
This website has a lot of information on solving pest problems, as well as professional strength products for weed control in lawn and garden. It’s a whole different world than the hardware store aisle.
Cinnamon has worked for me in the past…won’t kill them, but they hate the stuff and avoid it like the plague. Bonus, harmless to other (wanted) critters lurking about.
Get a bottle of TERRO (white box, orange lettering) from Home Depot. Get the bottle of the liquid kind or the individual traps. Set it near the wall or any small opening and watch it work. It will attract thousands of ants, all crawling over each other to feed. Don’t worry they will leave within an hour or so. And don’t kill them. They take the liquid back to the nest and kill the whole colony. It is the only thing that worked for me when I lived in Florida near the Everglades. I guarantee it!
I have also used Terro traps to good effect against Argentine ants in California. It does take some time to work but I have seen entire colonies die within a few days.