I can't believe how easy this has been! We have two coops in one run that is 4x8 and it has an attached run that is 8x12. There is a 4x4 coop on top of another 4x4 coop. We had 2 hens and got some pol pullets and they integrated in great after two days of showing who was boss. We put the chicks into the bottom coop at 4 weeks when the weather got warm. We left them closed to the run at first and let them free range with the big girls. At 5 weeks we opened the coop door half way so that they could go into the run but they had a place to escape. They did fine. The big girls would send them to their rooms some times (mainly when I gave treats lol) but were never rough on them. After they started getting too big to be able to keep the door half way opened I opened it all the way (maybe at 6 weeks) and they did fine. The big girls mostly ignored them. At bed time one little chick would go up into the big girl coop. At first we brought her back down every night. But then we started letting her sleep up there. A few nights later there was another chick up there. A few days later all 5 chicks were up there and one of the hens cuddled with them. Mind you this is a 4x4 coop with 5 hens and 5 two month old chicks! IT looks crazy crowded lol. And a completely empty bottom coop! To make it worse, Saturday I started remodeling the big run to turn it into a raised coop that will be 4x8 (actually a little larger) and the run will still be 4x12, which is a little small but they seem to ok with 4x4 lol. Anyway, while I am working on the coop, they have to stay in the run that is only 4x8. I let them free range when I am home and working on the coop. Though yesterday I was in Chemo all day so they were stuck in there until 4 pm! I hope to finish the other one today (I just have the roof and the wheels to add), but I am so proud of my girls for getting along so well. There is no pecking whatsover. The babies even steal treats from the head chicken and she tolerates it!