My flock is about a year old. All the same age and have been getting along great. Yesterday I noticed the rooster and some of the hens harassing anyone of the black stars. I broke it up, but it happened again today and she ended up flying over the fence. So I just let her free range for the day. The bullying is coming from the entire flock. They gang up on her and chase her and peck her eyes and comb. They’ve all been totally happy together for almost a year. What would cause this to start happening now??