I know what they look like. I've used pounds and pounds of Amdro (pre chickens) and still have them. The best I can do is keep them at bay. My chicks have been seen walking on mounds. Maybe immune like possums are to snake venom? Small fortune to eradicate where I live.Just get some dust and sprinkle it on every mound you find. Do you know what they look like? We’re on 2 acres in NC so fire ants are part of life. The chickens seem to naturally avoid the mounds (so do my dogs) but we don’t want them around. I take the dust with me when I mow the lawn and when I come across a mound I sprinkle it. Very easy and def doesn’t cost a small fortune!