My 6 bantam girls (6 months old) have taken to sleeping UNDER the coop at night instead of IN it. They used to sleep in it, so I'm not sure what changed. Not a big deal when the weather was decent, but it's now getting too cold at night. So every night I am out there in the dark, grabbing them one by one and sticking them in the coop. Once I get them in, they snuggle down and/or roost and seem to be fine. Any ideas on how to get them to go in on their own?