I added a rooster to my flock of 2 year old hens a few months ago, and this strange behavior started immediately. I figured everyone would quite down in time but it has yet to stop. Two of my "mean girls", who are 2nd and 3rd in the pecking order of the flock will attack my rooster and lowest pecking order hen when he mounts her. One will start pecking the head of the hen as the other one flogs the rooster of off her. Also, one of those hens will occasionally mount the lowest pecking order hen like she is breeding her, and this only started when I added the rooster. Why are they doing this and is there anything I can do to stop it?