There's no way you're going to keep them totally lice and mite free and actually our vet told us that a certain number of lice and mites are normal. What you want to avoid is the infestations. If you put DE in their dusting hole, I have found that ours won't touch it unless you mix regular dirt dust in there, too. I think they don't like the white color and different texture. You can always physically dust them with the DE. No you don't have to disinfect everywhere they go; ours our free range and they don't have much problem with lice or mites; we have more of a problem with the birds that can't go out of the pen, as far as getting infested with bugs. It wouldn't hurt to give all of them some vitamins for a few days. You can mix permethrin and water to make a solution to stand the banty in for her leg mites, if the vaseline is not helping, but I don't remember what the proportions are. If you're diligent with the vaseline, it will eventually work but it takes a while.
