My two older hens are such jerks. I get that they have to establish order but the chicks are 16 weeks now and terrified of them. They pull out clumps of feathers, chase them and don't let them eat. I have to put several food places out or separate them. They have plenty of space with a 10x30 dog run and coop is in my profile. How long will this last? The are 8 pullets, one roo. He's being picked on too.