I have a small bantam hen named Pearl. She has a "twin" I call Pippin. They live in a pen with a bantam rooster named Pepper and three small easter-egger mixes named Nutmeg, Cinnamon, and Buttercup. Pearl and Pippin are very small and remind me of white doves. Anyway, the last three nights I have found Pearl on top of the coop roosting instead of inside with the others. It wouldn't bother me so much except that it is cold here at night (upper 20's to 30's). She has never done this before. I have cleaned the coop and there is plenty of room for everybody. Fresh hay to snuggle in...They all seem to get along well, no fighting that I have seen. They have always been together and I have had them since they were all chicks. They are all about 8-9 months old. When I put her in she goes right to the group and squeezes in. I though maybe she was having trouble getting up inside the coop as it is off the ground with a ramp that goes into the bottom. Tonight I put her in the bottom and she climbed right up. I wonder if anyone has any ideas on why she wants to roost on the top of the coop rather than inside with the rest?