We had a bad case of mites in our coop. There were thousands of them. I tried everything until I found what worked. We used powdered sulpher and dusted every surface we could. Then, I mixed about a half of a cup in a gallon of water and sprayed the walls, ceiling and every crack. It took an out 5 treatments, but I finally killed them all. They come out at night so I had to spray each night she they emerged from hiding. It was really creepy because they crawled on me and got in my hair. Thank goodness it was easy to get them off! I never want to go thru that again!!