I added my chickens together 5 days ago. 4 older ones 3yrs old. and 6 younger 2yr. old. all hens. they did the usual picking and thought everything was ok, but one off the younger hens is taking a beating her head and neck are bleeding and picked at. she won't come out of the coop. put food and water in for her, she stays perched. what can I do? will the hen pecking stop? not sure why the singled her out.