Hi! We just have four chickens that we bought as chicks last summer. Yesterday I noticed that one of our Buff Orpingtons was spending all her time in the hen house. I haven't seen her in the chicken yard for a couple of days. I went out and physically placed her in the chicken yard. One of the other three chickens (Plymoth Barred Rock) kept chasing her back into the hen house. The Buff Orpington would come out and try to eat but the Barred Rock would chase her and try to attack her. I have enjoyed watching our chickens and I've never noticed this kind of behavior. What is going on? How can I help this chicken?