I have a small flock of ten, the latest two were added maybe four or five months ago. They have never once slept in the coop, they roost on the outside perches. I've never been worried about this as my run is completely enclosed to the coop itself. When they free range I've always been able to lock everyone up, including the ones who roost outside the coop. Now that it's getting cold at nights here I'm beginning to worry. My questions are what is too cold for chickens? Will these two eventually start to roost inside? Should I make sure they start roosting inside by putting them in the the coop and closing the coop door? They lay in the coop and are in and out throughout the day, just won't roost in there. Any input would be helpful, thanks!