I am not sure, but I believe my hens all have depluming mites to some degree. They all have a lot of feather loss on the breast and some are getting feather loss below the vent area. The skin in these areas is red. One hen has a scab or two on her breast around all this red skin. I have visually checked them over and I am not seeing any other symptoms but the red skin and feather loss. I have cleaned out the coop, dusted with DE, sprayed the floors, walls, roost bars and nest boxes with premethryin (sp) spray. Everybody was wormed a few months ago. What can I apply to the skin of my hens to kill off mites or eggs that might be in the feather shafts, help clear up the red skin and allow feathers to regrow? This is not a feather plucking issue between them. It seems they are pulling out their own feathers to relieve the irritation. Thanks so much!