Not sure where you live but I live in Texas, we have to deal with fire ants.
In Webster's Dictionary next to the word Grief there should be a picture of a fire ant!!!
I have horses and feed them sweet feed. A few years back the fire ants found the sweet feed barrel and moved in.....they were going to ruin a fresh 50# bag of feed.
Feed store grade DE did the trick!!! Sprinkled it on the feed, sprinkled it all around the feed barrel, Ta DAAAA, problem solved!! I also sprinkle DE in the nest boxes and have a dust bath of DE for the girls to enjoy.
Do a search for "food grade de" (diatomaceous earth.) It's great for preventative, but I haven't had much luck with killing. The main thing it's good for is drying up chicken poop, which makes it easier to clean up and it because it sucks out the moisture, the poop doesn't smell quite as bad, so I don't get as many flies and ants to start with. I use Orange Guard for pest control in and out and I love it..totally people and animal safe and smells wonderful. Good luck!
Quote:It looks/feels just like flour to the eye and fingers, but under a microscope you can see it's actually made up of tiny sharp edges. As the ants/et al walk through it these sharp edges scratch the exoskeleton of the problem insect and their insides leak out. The bugs die and their friends will vacate the area!!
I use it in my garden too, dust my plants and sprinkle it on the ground.
One nice thing.....it does NOT harm earthworms. The pest must have an exoskeleton for DE to work.
DE may keep fire ants out of feed, but it DOES NOT kill them in the mound. They walk right through it and keep going as white powdered ants. I'm sure it makes an excellent sunblock for them, but it does not kill them. Doesn't even make them move their mound. I'm speaking from personal experience of the last 2 months sprinkling DE on various FA mounds here in Florida.
If you are able to kill your fire ants with DE, more power to you. You must have some mutant ants, because these in my yard don't die unless I go nuclear on them.
Be sure and treat any mounds you find too. You might have to use something stronger on the mound to move them away from the coop. Water it in and keep chickens away until dry is supposed to be fairly safe.