Yesterday one of my four 2yr old hens, the dominant hen, was butchered. Later that after noon I put my four 15wk old chicks in a pen, and let the old hens out in the yard. They barely noticed each other. They would glance at the chicks then continue foraging. Today I did more integrating, and one of the chicks escaped the pen but I caught her in less then a minute. I don't even think the big girls noticed. I'm wondering if I should let ALL the chickens roam around the yard together before the big girls decide who's the leader. Is this a good idea or not?