When we got our run finished, we put the chicks and the brooder box into the run. My husband, very cleverly put a door in the brooder box and we would put them in at night. We did this at 3 weeks. Gosh, but the babies LOVED being outside. The we finished the coop. We had to cut a hole in the shed for a chicken door to the run and install a ramp to the coop. Got it all finished on Thursday and took the brooder box out of the run and started putting them in the coop at night. Here is my interpretation of what the screeching cries meant: "Oh no, oh no, oh no, oh nooooooooo, we're in jail, what is this horrible place? I'm scared, it's different, where's our box? Let us OUT!" I mean there was some caterwauling. Then the brave one looked around, decided it was cool after all, and hopped up on a perch. The rest followed suit, and now all if fine. But the initial freakout was too funny. Our temps are 90+ in the daytime and 70 at night. They are fully feathered out and fine. There's a reason why being afraid to try something new is referred to as "chicken".