First:I have 6 hens and one Rooster in a fenced run/coop. They are all at least 26 weeks old. My father-in-law said he noticed some of the birds pecking and eating some feathers off each other. I have yet to see this myself but several of my hens have bare spots on them, all of them where the tail feathers meet the lower back. I noticed that when the Rooster mates with them, that particular section of feather tends to get ruffled as show below. Is the Rooster doing this? Are the hens not getting enough vitamins (my FIL's theory)? Or are they molting?