We lost a hen recently and her sister is behaving in a really aggressive manner towards the other hens. She doesn't want to let them in the coop and is pecking at them. Feathers are flying. The hen we lost (she'd been battling an illness) was the top of the pecking order even while she was ill with this one right behind her as second in command. I'm wondering if this behavior is normal and she's trying to assert her new position as top hen or do chickens grieve as we do? Not sure if there is much I can do but there's some serious stress going on in the coop tonight. I didn't notice this behavior last night but tonight is pretty bad. Any ideas?