I have a 3 year old Rhode Island Red hen that is in a large-ish coop with 5 other hens. In addition, they have a 60' x 80' fenced yard that they run in. She has lost most of the feathers around her head, is loosing a fair amount all over her body and the feathers that remain are pretty ratty looking. I'd say she was molting but no one else is (last time they all molted together) and I've never seen them loose their head feathers (although I'm pretty new at this so....). Should I be worried?