Turtle is right. You don't want them to sleep in the nesting box. Make them a roost as turtle says. Make it from a 2x4 with barely rounded edges. In the summer, let them perch on the 2 inch side. In the winter, let them sleep on th 4 inch side so they nestle down and cover their feet with their feathers to keep them warm. If these are young chickens, they should not perch until about 12 weeks to prevent a crooked keel bone.
Oh, wow, yeah....they should be perching. If they sleep in the boxes they will crap in there and then the eggs will be messy...I still have an old SLW that stubbornly sleeps in the box (she was a second-hand chicken from a friend) But amazingly enough, she's potty-trained herself somehow.....I have no idea, but she used to poop in it when I first brought her home, and now I see her poops on the wire floor just outside the box and there's none in the box....but she's the exception. Chickens are much more comfortable roosting.
