I found that tea tree oil killed off mites. We had an infestation of mites and did the Sevin and Ivermectin Pour-On for Cattle on the girls. I used the Sevin in the coop and sprayed the coop with tea tree oil in all the cracks. The mites were crawling on us and we sprayed the tea tree oil on us and the mites died right away. Good luck!
Tea Tree Oil is some of my favorite stuff! It is Anti-fungal, Anti-Bacterial, Anti-Viral and can be diluted with a carrier oil and still be just as effective. We have used it on pimples, scratches, pink eye (look up usage directions) and many other things. Can't say enough about it. Puritan's Pride usually has the best price on it. I have heard and experienced how Peppermint Oil is an effective Ant repellant. I wonder if that would help with mites....