I have used permethrin dusts which I am not fond of. Masking myself & dusting is still a messy procedure. This ProZap dust toasted the lice but is not eradicating the mites as quickly as I expect. I am on the second week of treatment dusting all birds. The coop was cleaned completely & treated with Permectrin 2 from ceiling to floor. My chickens all have 3 acres to range on & I'm aware that wild birds are carriers. I have heard that one drop of Eprinex at the base of the bird's neck can eradicate external as well as internal parasites & there is no danger regarding a withdrawal period for egg consumption. Has anyone had any experience with this product? Here is a link for it: http://www.northstarcooperative.com/NSC/Products/ivomec_eprinex.htm I used to use Ivomec for swine which is made by the same company & it seemed to work well. There was a withdrawal period for it though.