Can someone please tell me if our rooster is responsible for the bare backs on our hens? My hens are about 10 months old and the rooster is the same age. We have one RIR rooster and 5 hens. The barred rock hen and the americauna hen have bare backs but the RIR hens do not. Is this something to do with the breed? Any suggestions? I really appreciate all of you knowledgeable and experienced chicken owners out there!