My 6 month old chicken (one of 22) has a large scab (maybe... it's so strange looking I can't describe what I'm looking at) and all the feathers under her tail/vent are all gone. I just came home from a 3 day trip and someone else was watching them, so I don't know how long this has been going on. I was told there was a bloody egg yesterday. I gave her a warm bath and checked her out, sprayed peroxide on. She seems fine otherwise, but when I put her in the coop (she's separated from the others) she started pulling out feathers between her legs. Should she rejoin the coop..? Any ideas about what this might be? Thanks in advance.