My rooster decides who does or doesn't get to roost. He has the prime spot by the window, the two broodies are in the nest and then he seems to have a special girl who gets to be next to him, I don't know how he determines the rest of the order but some are allowed and some are not and the roost is surely big enough for twice as many chickens but I've seen him chase a couple of girls off and then he lets them up there the next day. Weird.
