OMG, I to am having the same problem, last night I went out at 9:00 pm and all the ladies were sleeping in a corner in there run. I scooped them up and put them in the coop. They are 6 weeks old, pretty much all feathered, but we are still having some cold nights so I leave a heat lamp on in...
I too started with 7 Buff Orpington's they are 5 weeks now are really enjoying their coop. I could spend every waking hour just watching them. This weekend I am planning on doing some painting to give them some color to look at.