I know this sounds strange, but I heard the chickens making a lot of noise, way more than usual and walked out to find one sitting on the smallest and another pecking at her tail. I pulled the injured one out, but ended up separating the pecking one later. These are young birds and the one pecking we named nudge because of this behavior. I swear it looked like a gang beating when I came out to check. Pudge is the larges and an americauna. She does not peck at all, but was the one sitting on the other. I couldn't tell if she was helping or trying to protect. We had found one dead the day before and I think it was the same behavior. We don't know why nudge does this. It's almost like she is bullying them. She is very aggressive and I am afraid that even when we put them in the coop, once we get back from a trip, that she will still try to do this. Leading up to this, nudge was the only one who still had full plummage. everyone else has been pecked bare on their backs. What do I do with this aggressive chicken??? We want to replace the two that were killed and prevent her from killing any others. Any suggestions??