Hello! This is my first post on this forum, so I hope that I'm posting in the right section. We got 12 chickens in April. Four Black Orpington, 4 Americaunas, and 4 Buffingtons (we were told they are Buffingtons, but can't find them in any books - they're yellow). This is our first time raising chickens. We built a nice big pen for them to run around in and play. They've always seemed to get along really well with one another. Today, I noticed that one of the Americaunas was missing all but one of her tail feathers. She fluffed herself up and I could see that where the feathers came out (the quills?) is all bloody. As I was watching her, another Americauna started pecking at her back end where the blood is. She's not bleeding to where if you hold her you end up with blood on you. It's just the stem-type part that the feather got pulled out of that has blood in it. We have her isolated from the other chickens right now. She is locked in the coop and the other ones are still out in the pen. We are totally new to raising chickens, so I'm looking for any advice or suggestions on how to handle this. Is it OK to let her with all the chickens in the coop tonight since it's dark in there and they won't see the blood? Do we need to keep her isolated until the blood is gone (this is going to be tricky at night-time)? Any ideas as to why this is happening? The chickens are in a 16' long x 6' high, x 4' wide pen - we were told that that is plenty of room. They have one feeder and waterer that they have access to at all times in their coop and one large waterer in their pen that they have access to until I lock the door to the coop at night so that no predators can get to them. I take fruit and vegetable scraps as well as scratch out to them in their coop every day. I'm completely lost as to what I need to do. Any advice, thoughts, or suggestions are greatly appreciated. My son and I are distraught with this. Thanks!