Sevin dust is an insecticidal dust with the active ingredient (ai) carbaryl. Below are several informative links for carbaryl info.
http://en.wikipedia.org/wiki/Carbaryl
http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=19022048...
The Sevin dust works!!! Mites are dead. So far, no visible effects to our chickens whatsoever. We did not dust the chickens, only the coop and the new bedding while they were free-ranging.
We have been battling red poultry mites in our duplex coop now for a couple of weeks. We removed and burned all bedding, power washed the coop, painted all cracks and crevices with white wash (made with hydrated lime), lined the coop with boric acid and then dusted the crap out of it with...