So, I found a nice large branch in the driveway after the last wind, so I popped it into the brooder with the chicks. I've seen a couple walk on it, but most of the time they just hop over it or ignore it altogether. When do they start to roost? They are 4 weeks old. The brooder is a 4'x8' box, 2' deep, with 25 chicks in there. Lots of room to run and play for now... so the branch isn't in the way, at all.