I am having the same problem! Only one of my chickens is eating the feathers. They have plenty of high protein food, calcium, and fresh water. I feed them alfalfa pellets soaked in water the night before for added protein. I even add sunflower seeds to their scratch for extra protein as well! They have lots of room to run around, so they aren't confined. I have also tried blue kote (which turned them purple) and apple bitters. We don't have a rooster, and it doesn't seem to matter what color they are. I have a black sex link, a golden laced wyandotte, a red sex link, a rhode island red, and 3 buff orpingtons. The one that is eating all of the feathers is the buff orpington. She isn't on the top of the pecking order, and she isn't bullying. So I decided I have had to block her off from the rest of the flock, as they all had missing feathers on their butts and thighs. On one of my BO's it was so bad her bottom was completely bare! And on my GLW she was eating the feathers off her back! There wasn't any blood drawn, she just pulls out beakfuls of feathers and chows them down like she is starving! I call her my feather addicted chicken! Some of the others started on that habit, but once I blocked her off, they stopped. I am happy to say their feathers are finally starting to grow back, but I just feel so bad leaving Sandy all by herself. I put her in with the rest of them at night, then in the morning I put her in her own area with food and water. I just don't know what else to do, it's been a month now. I tried putting her back in with the others after a couple of weeks, but she went right back to it. It gets really bad when the others are taking their dust baths. I love her so much, and I can't get myself to give her away or cull her. So, I'll be watching this post for other ideas. Good luck, and thank you for posting this question!