We have 8 hens and a rooster. One hen has always preferred to roost outside. But recently, another chicken...and a 20 week old one as well...have also been roosting outside. We redid their coop and its clean. Any idea why these other two joined the 1st? Also there is another 20 week old that stays in the coop at night. During the day the 2 newer ones hang out tho....weird.