Alpha hen, Cricket, seems to be trying to kill her best friend. She is chasing her around the coop, jumping on her while biting her right behind the head and not letting go until she rips feathers out and the other hen runs away only to be chased down and have it done again. They have been kept together for nearly 2 years now. I did take Charity(the one being picked on) out for a few weeks while she was sick. But, that has been nearly a month ago now. They had already established a pecking order. Why is she doing this again time and time again?? What can I do to stop it??