We've got an A frame tractor coop. I know that chickens are supposed to roost. Is there a physiological reason why they should? My girls appear to be sleeping either cuddled together or individually in the nesting boxes. Is this okay? There's usually not poop in the nesting boxes. I can try to get my hubby to lift up their roost a bit, but their coop is not that high inside (floor to ceiling). I think it's just not high enough for them. Opinions?