We have four Red Star hens (almost 2 years old), and 11 Barred Rock pullets (about a month and a half old). The Red Stars and Barred Rocks are in separate coops (for now) but are in the backyard together. All free range for a good bit of the day. My husband caught one of the Red Stars and showed her to me. She has a bare spot under each wing - just under the part closest to the "shoulder". I don't see any blood, but there are NO feathers. Maybe about an inch to two inches roundish. Neither of us have seen pecking behavior from one hen to the other. So, what on earth is this??? Should I clean it? How long do we keep her separated?