Hi all, We're still new to this chicken thing, but recently we've noticed one of our hens was missing feathers towards her backside. Her skin is red and very dry looking. We've inspected thoroughly, cleaned out the coop, and I don't think we've seen any indication of mites or lice. Now we are noticing red bare spots on three of the hens, and feathers here and there in the coop and out in the yard. The gals are acting healthy, seem happy and still laying. Any thoughts on what this is and what we should do about it?