One of my RIRs, Big Red, 8 months old and at the bottom of the pecking order, refuses to get on the perch at night. Big Red and the roo pal around during the day ... I think she's his regular girlfriend, but he roosts with the older hens on the front perch to maintain his status, I assume. Big Red's sister sleeps on the back perch. There is no one to keep BR from getting up there. I generally go out at dark and put her on the back perch next to her sister, and she stays. If I go out a little later than dark, I find her sleeping in the hay, under the birds on the front perch. I don't like her to sleep there because the other birds poop on her. The advice I've read says be consistent and eventually she'll start roosting on the perch on her own, but she hasn't. She's capable of getting up there ... any other ideas?