After I changing the hay last time in the chicken coop, they started sleeping on top of the coop. They've always slept inside and when I changed the hay I used the same one. I changed the hay then we left the coop door open and went out of town for a few days. The day we got home we noticed they were sleeping on top of the coop. We put them inside and the we're trying to fly out. We let them out and now they have been sleeping outside for about 4 weeks. They still go inside during the day to lay, but they won't sleep in there anymore.