I've determined that, so far, its just one chicken feather picking- an Ameraucana. She's being really aggressive with it. I've tried baking them a flock block, which they love and pecked at a lot but it wasn't enough to deter the main culprit. I also tried spreading grit, their crumbles, and rolled oatmeal on the floor of their (88 sq. Feet) coop. I've also tried hanging kale (they didnt get that at all), giving them watermelon, cauliflower (didn't get that either) and today I'll try lettuce. We don't have a run at the moment for various reasons but we are tryin like h*** and have been the last couple months. To make matters more complicated, I also have three birds that are confined in a cage within the coop that I'm trying to integrate into the other 5 birds. i can't free range them because our property backs up to woods and is full of predators. I also don't have a roo. I've gotten so frustrated with the situation and with the Ameraucana that she is now alone in the chicken tractor outside a window where I can see her. I'm so frustrated and upset at this ongoing situation that my brain has locked. I'm really hoping someone on this forum can help me.