I recommend Permethrin spray for the mites. Most feed stores such as Tractor Supply carries both the ready to spray and the concentrate that you mix with water. Spray inside their coops spraying every crack and crevice, on and under the roosts, inside and out side the nest boxes, ceiling, walls, everything. I had mites for the first time ever this past summer and the birds were terrible. I initially sprayed weekly and eventually got rid of the mites but the birds looked terrible. I used permethrin poultry dust and dusted the birds good. Now the birds are now looking much better and no more mites. I actually gave the birds flea baths thinking it might kill the mites and it did some but there were a few after the baths. The mites can feed the life out of the birds if not treated. The mites can hide in the cracks and crevices in the coops so just dusting the birds may help but spraying inside the coops kill the mites but it does not the kill the mite eggs so a thorough spraying is needed with followup sprays so when the mite eggs hatch they will be killed too. Just my opinion.