This morning I went to check on the chickens and found one of them (named Lucky) all bloody. She has a 2" x 2" area just above the tail feathers that has been plucked clean and the whole area is raw. I removed her from the flock. She is moving around fine and is happy to eat and drink. I'm just wondering what I need to do immediately to keep her safe from infection. Then, how do i reintroduce her to the flock? I have 2 adult chickens (Road Island Reds) and 8 2-month-olds; 2 Reds, 2 Barred Plymouth Rocks and 2 Buff Plymouth Rocks (including Lucky). No Roos. The adult hens bully the chicks anytime they can, but they are still in separate runs, so I know they aren't responsible. Any advice is appreciated!