I thought it might be mites, so I completely cleaned out the coop with vinegar and dusted the birds and the coop with Sevin. Repeated the dusting a week later, and another week later....I don't think it's any better! I can't tell if they are pecking each other or if it's pests! This has been going on for months! (I first posted in December.) It started with just one bird balding, then two...now 6 of the 8 have bald spots! Two of them have feathers missing from the TOP near their tail feathers, the other four have bare butts! Ugh! They appear happy and healthy and most days we are still getting 6 to 8 eggs! Help!