We recently built a new coop and bought 12 chicks. They lived in the new coop for 4 months by themselves while our older 6 lived in the old coop. When they were big enough to go out in the run, we let them out for a few days and then brought the big chickens over. They are all fine in the coop itself, but the big ones control the outside. They will attack any of the babies as soon as they step outside. It is getting colder now so none of them are out as much, so they are okay for now. However, I need to find a way to let them all be friendly while outside once Spring comes. I don't want 12, one year olds being trapped in the coop for the rest of their lives.