Hi - my Buff Orpington suddenly started losing feathers a few days ago - they're scattered around the yard and in the morning they're carpeting the coop. At first I thought maybe she was molting - I don't even know if this would be normal but didn't know what else it could be. But neither of my other birds are losing feathers at all. And it seems like most of them are coming from just below her tail feathers - there's kind of a bald patch there. I thought of mites but I don't see any on her or in the coop. And her egg production might be down but she has never been a great layer compared to my barred rock and RIR. What does this sound like? Thanks!!