I have a young chicken that is losing her feathers on her head and around her eyes. One of her eyes is very red around the edges and her eye looks sick. At first I thought she was just being picked on, but the bald spots have spread. I think another chicken may be starting to lose some feathers on her face also. I don't see any signs of mites in the chicken coop. Does anyone have any ideas as to what could be causing their feathers to fall out of their heads, and around their eyes?