I have a flock of nine hens. For a week they have been picking on one of my Ameraucanas. This behavior seemed to come out of no where. They are no open wounds just a lot of feather picking and chasing. The put upon hen spends most of her time hiding in the coop or if out in the yard seeking cover from the other aggressors. Is this behavior that will pass or is this poor hen in for a lot grief? There seem to be two other hens that are the primary aggressors but I have seen others pick at her also.