My 5 week old chick sleeps on the big roost now alongside the grown-ups. Betty still cradles it under her wing if it's chilly, and during the day she still chases off certain hens that get too close to her baby. The little guy thinks he's all grown up though. The older chicks are 10 & 13 weeks old and sleep in their grow out coop but are free to mingle with the older group during the day. They weren't hen raised and still haven't figured out they should go inside at night so I go out and toss them in long after the big coop is sleeping.