I just "winterized" my coop by by placing a piece of plywood over an open section of the coop since it's finally starting to get cold. I went out to close the door and took a quick peek inside and noticed they were all on the ground instead of their roost. They're always on the roost every night, so this struck me as odd. I went back and checked again and they still weren't. Finally I just grabbed each one and placed them on the roost. They seemed to stay. This is the first night of having the plywood up, so should I not worry and they'll finally figure it out. Anything to worry about? This is my first winter with chickens.