I have 13 pullets, and tonight they decided they'd rather roost on the fence instead of in the coop. I put them in, and when I couldn't find the 13th hen, I found her perched in a tree. She won't come down. What would cause the change in preferences, and will my little buff orpington be ok in the tree all night? I live in southeast MI, and it will be in the 40's tonight.