I use Amdro but keep the chickens away for a day or 2 by putting a wire screen over the mounds and after the 2 days shovel out the Amdro remains that the ants return to the surface.
I have had a couple of chickens eat a small amount after the ants extracted the chemical (just several grains) with no apparent ill effects. The best time to put out the Amdro is just before a rain or early in the morning the ants will almost immediately collect the bait and take it to the mound and later the same day return the husks to the surface that is when I remove it with a shovel and the ants will die in a few days after that.
I have had a couple of chickens eat a small amount after the ants extracted the chemical (just several grains) with no apparent ill effects. The best time to put out the Amdro is just before a rain or early in the morning the ants will almost immediately collect the bait and take it to the mound and later the same day return the husks to the surface that is when I remove it with a shovel and the ants will die in a few days after that.