looking for help with a flock that has begun picking on one hen (10 hens, 1 roo) they have all been together for over 1 yr..tried isolating the one hen, then reintroducing her at night with some pine tar on her comb but that did not work..have a 200sq ft area elec fence and she makes a bee line for the henhouse and hides in a nest..need ideas. thank you