I have 6 girls, age about 6 months. I have two BO, two RIR and two black sex linked. They are not free ranging and have a 12 x 14 foot run to themselves. All are laying eggs and have seemed happy until recently when I noticed that Frances (one of my RIR) has a patch of feathers missing on her throat. So I have been sitting with them and observing their interactions to see if someone is picking on her. Well at least three of them are not only picking on Frances, but the other two as well. Every time they are in proximity to each other (particularly problematic when they're roosting at night) they're pecking and poking at one another. I even saw one of my black sex linked picking downy feathers off Cornelia (my other RIR). It's gotten so that I can't keep track of who is picking on who. What could be causing this? I had changed their feed to pellet layer feed and they didn't care for this and so I switched them back to the crumbles and they are gobbling that down. I try to provide them with a varied diet and throw scratch and seeds for them to forage for. I forget exactly how long my roost is - about 5 feet I think. And there is a higher roost about three feet long but nobody seems to want to use that one. These are my first chickens and I've had them since they were two days old. Wondering how I can get them to play well with one another again.