I've never had a group of young chickens just move themselves into the big girls coop but tonight when I went out to close everyone up, one of 9 of my 2 month old Polish was on top of the coop with my EE Roo. I'm thinking that's odd since that one is a girl (I've had a couple of the boys try to join the roo)....then I realize she's kind of lost. So I get her down, put her in the smaller coop I have for the young ones and I realize that it's empty! I look in the big coop and there they are, all nestled on the lower roost I put in the for "jr's" that they never used. Went back and got the lost one and put her on the ramp up to find her spot. I've never had 9 chickens in one night, move themselves into the big coop! They free range all day and share a run with my other chickens but they've always gone in their own coops at night.... We're in the process of building them their own coop...guess we better get busy. I hope they like their new digs because I think this group is a little picky about their house!