I have one hen, a barred rock, that has been pulling feathers out of three of her flock mates and eating them. I have 18 hens and it seems as though she is the only one doing this. I currently have her separated from the other chickens (in a crate located inside the chicken coop), and I would like to integrate her back in. What are my chances that this isn't a behavioral problem, but more likely a protein issue? I currently have all of the chickens on a 16% protein layer feed. Should I offer more protein, and if I should what is the most cost and time effective way to do that?