We added 4 baby chicks to our 3 hens we have had for 1 1/2 years. One of the chicks turned out to be a rooster. As soon as he matured into his rooster self he started picking on our original 3. One lost quite a few feathers on her back and our one small breed had been pecked so many times on her head she was bare of feathers and bleeding. The original 3 are afraid of him and he only protects the new 3. Its like we have 2 separate flocks in one coop. How do I keep him from doing that?