Thanks to everyone who replied. I finally figured out the problem - pecking! As I was observing my girls free ranging in my backyard, I saw Crystal going after ankles and biting them! I isolated her immediately in the chicken tractor, away from the others. After a few days I started to let her free range with the others. I took almost a week and she seemed to be getting depressed. I put her in with the others at night and found no new injuries the next morning. While I did succeed in "breaking" Crystal, the saga continued. A few days later four of the chickens all had bloody ankles and I observed Ravenclaw going after ankles. I isolated her, but as she was head chicken at the time the entire process took much longer. I kept her in the chicken tractor away from the other chickens for four weeks. I allowed her to free range with others for a short time each day. I was fairly certain I was going to have to put her down, but a friend of mine encouraged me to stick with it. A few days ago there was a shift in behavior. Ravenclaw and Hera would be perfectly still staring at the same spot at the ground - like a stare down - and Hera would then walk away leaving Ravenclaw still staring and perfectly still. Then, on Christmas eve both Hera and Ravenclaw were wanting to lay an egg at the same time in the chicken coop. They were really noisy and I stayed for awhile observed them, but there was no pecking. I felt the time was right, and I put all the girls together in the run and for the night. Christmas morning I checked the girls and they were all okay! So far so good. It was a lot of extra work for me but I am really happy that I did not have to put an end to my Ravenclaw. Merry Christmas!