Mites will live in the nooks and crannies of your coop, not just in the bedding. An other favorite hiding place is in the nest box. In order to get rid of a mite infestation, you'll need to do a complete clean out, wash with a product which will kill them: you could use liquid dawn and bleach or vinegar. You'll need to be sure the coop is dry and no more odor from the cleaning agent. Then you'll need to dust all of the nooks and crannies with a safe to use insecticide. I used permethrin garden and poultry dust. Pay special attention to the roosts and nest boxes. I use a gloved hand to apply the dust to the perch and rub it in, and get a nice dusting in the crack where the perch meets the wall. You'll also need to dust the birds at the same time. You'll need to burn the shavings, or otherwise get them off your property. Then, depending on the temperature, you'll need to repeat this whole process again in one week to 10 days whether you see any mites or not. When I treated, I also used ivermectin pour on on the birds, (not at the same time as using the dust) and also treated the area around the coop. Since using aromatics in the nest box, I've not had any mite issues in the coop.
