I have a rhode island red who suddenly started attacking, to the point of blood on the head, one of my other hens. I separated them all day, and have opened up my whole yard for more space, but the victim is terrified to go anywhere near the other now. How do I tell if the attacked hen is diseased and that's why the one is singling it out? or if the rhode island red is going to start picking off my flock one by one? Anyone else ever had this happen? And, if so, what did you do?