The chicks have become such good flyers (not fryers!!), we had to move them into the coop. In the last picture, you can see they spend time preening. I don't know how the feather growing process works, but it looks like the adult feather grows from the same pore where the chick feather is, so at the tip of the adult feather is the chick feather, which eventually rubs off and floats around the corners of the coop.