I'm a big fan of Diatomaceous Earth lis known to kill all insects including pests and best of all its completely non toxic. Research it. I always use food grade. It's recommended that you dust the chicken or (whatever animal) and avoid letting them breath it if possible. It works by dehydrating the pest. Also works on dogs and cats to kill fleas and ticks. It don't kill at once but it does after a short while. Dust it around areas where the mites will travel and do all of your chickens. But it would be best to research it and see for yourself exactly what to do in detail.Ive never had mites in my chickens but I did read about it. It's very affordable too. You can find it at building suppliers like Home Depot or many hardware stores. Or you can order it in ebay or Amazon. It's even used for ridding house of roaches ants and spiders. Also used to kill head lice. Many many uses. It is powder and I keep it dusted at door entrances to keep any bugs out. And I use it on my dogs and cats and it works. It doesn't harm them if they lick it. It can even be put directly into cat food, dog food and chicken food to kill intestinal parasites. It even recommends humans can take some in juice or whatever to kill intestinal parasites. Just saying. Good luck.
