It's supposed to be in the 20s tonight and just to give my parents peace of mind I'm willing to put a heater in the coop. The only bedding in the coop is in the nesting boxes. I'm not sure if our 7 hens need it though. Our cochin goes on the bottom roost, a leghorn and EE on the middle roost and 4 leghorns on the top roost so they're not really bundled together. Heater or no?