Poultry protector, poultry dust, and i have even heard of washing with cat flea shampoo. Be sure to also clean out the whole coop area, run, nest boxes and spray the entire area with a safe pest solution. (remove your birds first)
The first video on this link is so adorable! It looks like the chicken enjoys it. I think it is from England or Australia, because they call DE 'Diatom'. DE is another thing you can use to dust your chicks. Haven't seen all the examples on this link---it was the first one that I had seen awhile back.
I use food grade Diatomaceous Earth. I put it in their nests, their food and sprinkle it on the wood shavings in their coop. This keeps a lot of parasites down.
The food grade is safe for us. I am asthmatic so I am very careful about dust. You don't need to use a lot on the floor. I sprinkle it on the roosts, too, to kill any mites. It is finely ground up fossilized sea shells. The sharp edges cut the soft underbellies of insects, dehydrating them to death. I keep some in the feed so I don't get moth larva. You can apply it directly on your pets, I just try to apply it so the dust doesn't go directly in their face. I use it in my garden as well.
The non-food grade DE is full of silica. DO NOT use that! I spread it throughout my house years ago to control fleas and it my lungs were a mess!