I am also about to add new chicks and they are varying ages from 4-8 weeks. I have an established flock of 4 and 6 new chicks. We have the chicks inside in two brooders right now and when its warm out we put them outside in a small enclosure we built of scrap wood and extra chicken wire from our coop. This allows them to be outside with the larger girls, but still safe from them and predators. My Cochins seem pretty accepting of the little ones and haven't gotten aggressive, but the Wyandottes are vicious, going after the chicks with a vengeance. My plan is to continue to keep the chicks separate and put them outside more often as it warms up, but in the enclosure until they are full grown. The problem is that the larger chicks are too big for the brooder, so I need to get them outside more and I think what I am going to do is put an enclosed box in the coop for them to sleep in at night so they won't be attacked by the other girls, but everyone will be accustomed to them being in the coop. I think keeping them in the enclosure during the day Will keep them safe and allow them to stay on chick feed until they are large enough to be set out with the rest. Any thoughts? This is my first time adding new chicks and I really need to get these big chicks out of the brooder, they are like monsters in there with the smaller ones.