I received an email from Jen, asking about a mite infestation in her chicken coop, and if I knew any non-chemical remedies. We've never had a mite problem (knock on wood). I do have some old poultry reference books, so I did some research for her. I thought I'd post my reply:
When I showed your email to my husband, he said your deep straw bedding might be part of the problem. It might give the mites a place to hide out and breed. I don't know about that. We have a coop with a slatted floor, droppings pit underneath, straw only in the nest boxes. Figuring out a way to keep wild birds out of your chicken coop might prevent them from bringing in mites too. But since the mites are already there, here are a few folk remedies you can try:
*give the chickens a dustbath box or pit filled with wood ashes - it's supposed to suffocate mites. We have an open burning period in the fall, when we can burn weeds and small brush piles. Our chickens love to get out in the burn pit to dustbathe.
*try dusting your chickens with diatomaceous earth - hold them upside-down and get it down underneath their feathers to their skin (but not in their eyes); you can also put it in their feed.
*Red mites hide out by day in the cracks and crevices in wooden roosts and nest boxes, coming out at night to feed on the chickens as they sleep. To check for them, pluck one of your chickens from her roost at night and look for the mites beneath her leg feathers. A folk remedy is to chase all the chickens out of the coop in the morning, locking them out for the day. Wet down the roosts, especially underneath, and bottoms of nest boxes with a 50/50 mixture of used motor oil and kerosene, using a paintbrush or dabbing with a rag. Keep the chickens out until as late in the day as possible. You might have to repeat the treatment after 2 weeks.
*If you can see the mite, it wouldn't be scaly leg mites - they're microscopic, causing scales that stick out, and sometimes fall off, on the naked part of their legs. Washing the legs then rubbing in Vaseline, or dipping chickens' legs in salad or baby oil weekly is said to work for that.
*Depluming mites cause the chickens to pull out their feathers to try and stop the itching, leaving your chickens are almost naked. Dunk the bird, wetting it all the way down to the skin, in a mixture of 2 oz sulfur plus 1 oz soap per gallon of water.
*Last Resort - chemicals: Sevin (carbaryl) as a dust or spray, or Co-Ral (coumaphous) dust. This is the only treatment I could find for northern fowl mites, reddish or dark brown ones that spend their whole life-cycle on the bird. Look for them around the tail and vent during the daytime. If the infestation is severe, they could be on the eggs too. Insecticide powders in the feathers of a mother can kill the chicks underneath her, so any treatments have to be done well in advance of hatching.
This is Baldy. No mites here - the photo is from earlier this fall when she was molting. When the days get shorter, most of our flock lose their feathers, stop laying eggs in order to grow new ones, and then are all nice and newly fluffy when the cold weather gets here. Then, when the days start getting longer after New Year's, they start laying eggs once again.
When Baldy was a young chick, on her first day in with the rest of the flock, she found a small hole under the chicken pen fence just large enough to squeeze under, but not all the way through. The rest of the flock, vicious little beasts that they are, pecked her on the head as she lay trapped. I thought they'd killed her, but when I pulled her out she was still alive. I took her inside, sprayed her head with liquid bandage, and after a couple more days in the house she rejoined the rest of the flock. Her head comb never did grow back, though.