Just researched it quickly, and it is Carbaryl. Silkie chicks have been hatching in a pen with four Moms who laid their eggs on the floor--they didn't like nests I'd put in there. I had recently dug out several inches of litter and soil in there, sprayed the entire coop with Poultry Protector, put down DE and hydrated lime and new pine chips. Nevertheless, the chicks were hatching with mites on them. Even had mites on an egg I removed. Fearing the mites more than Sevin, I put a small amount in one hand and carefully rolled each newly-hatched chick in it before placing them in the brooder. Some of the chicks are now two weeks old, and there have been absolutely NO problems.