Hi! Just a newbie question... My four pullets and once cockerel don't like to return to their coop at night. Their pen is entirely enclosed (top, too), within a fenced in back yard, so we aren't overly concerned about predation. However, I thought chickens naturally returned to the coop at night. It's summer in Mississippi...quite warm, and they have been sleeping all night on their outdoor roost. It's about four feet off the ground. I have checked on them off and on throughout the night, and they've definitely been staying out. They are about three 1/2 months old. Is this ok? Should I be encouraging them indoors at night? Their coop door is open for them, so they can go in and out at will. Thanks.