Hi! I have four hens that are six months old. They were raised together since they were two weeks old. Everything has been going wonderfully until a few days ago. My Isa Brown started pecking the smallest Americana. She pecks at the back of the neck, trying to grab feathers. Tonight she went after the other Americana that she’d been hanging out with all day. This happened on the roosting bar. Is this normal pecking order behavior or do I have a bully/major problem. My girls are in a coop that is designed to hold six chickens. They get to run in the yard almost all day. They are on a layer feed. Sunflower seeds and mealworms are given daily. Thank you for any feedback!