I have 4 hens. My 2 Wyandottes pick on my Easter Egger ... badly. We noticed 2 days ago she has no feathers on her rear end. None. When I'm outside I try to stop them ... but obviously can't be with them all day. I've read to separate them but then worry it will start again (and honestly not sure how to separate them). Is there anything I can do/give them to help??