I have a hen that is about 4 months old. I think she is the next in line to our large rooster. I went out this morning I noticed all the feathers on her back were gone. They looked like they had been plucked out. She was alert and was looking around and eventually got up and walked around. Two of the patches on her back had a lot of what appeared to be very small larva crawling all over it. I am wondering if it could have been the rooster? We are new to raising chickens. I put some sevin dust on the mites to kill them. Does she need to be secluded for safety? Will it harm her standing in pecking order? Need help! thanks!