I have 11 chicks, ranging in size from barely smaller than my full grown hens already in the coop, to just about the size of my two fists together. I'm trying to figure out when it is safe to put them in with the rest of the flock. We have two hens and a rooster in the main coop already, and they killed one of the chicks when it got out of the baby pen, as we call it. I know the two largest chicks will be fine. They are feisty and are the same size as the smaller of my two hens, but I'm trying to figure out how to tell when it is safe to let the rest out in the main coop. They are all different breeds, and the chicks were purchased after we had the three others for a number of months.