Ugh, I hate mites. Alright, what I do when My hens got mites is I dusted them with 7 dust, and then completely deep cleaned their cool with vinegar. That means removing all bedding, scrubbing all sides, getting into every crevice possible. After that I dusted the whole coop in seven dust, and put clean shavings on top. SHAVINGS, not straw, mites can hide from the dust in the hollow straw. You have to go through this process every week for a month. ( or I did ). After they are completely gone, for a preventative, I bought cat flea stuff, and put a few drops of it by their vent. This soaks into the skin, and help prevent any type of pest. Hope I helped!