I have 26 hens and 2 roosters. We had a coop built for them with lots of roosting areas...but they won't roost! There is one roosting place about a foot and a half off the floor and they will roost on that, but no higher. They are about 15 weeks old. Any ideas? Most of them just sleep in a pile on the floor. The coop is a good temp, insulated so it isn't cold. Thank you!