We have two different ages of baby chicks, one group of eight is 4 1/2 weeks old and the other group of 5 is 2 1/2 weeks old. We had the groups seperated for the first week, then had them in the same big area but with netting between them so they could see each other but not be together. Next I put a thing in there that has a bunch of slots that the youngest chicks could get through but not the oldest chicks. That way the youngest babies could go back and forth but could escape if picking went on. I checked on them almost every hour or at least several times during the day. Today I changed the area all around and they are all together in one big area. There is a light on each end in case they need to be warm but not together, if that makes sense. To my amazement everybody seems very happy and the older chicks seem to be almost mothering the babies, especially the older buff orpingtons. I know they can be great mothers but the way they are acting this young surprises me. Out of the 13 chickens the most of any one breed is two so it is definitely a mixed flock, ranging from White Leghorn, Buff Orpingtons, Buff Minocras, Buttercups, Rhode Island Reds, Barred Rock, Ameraucanas, and one surprise chickie. So far, everybody is happy and life is good in the Wheeler henhouse.