We have a well protected coop with a roost and nesting boxes which is heated with a red heat lamp. We have a couple roosts outside in our run and our girls are spending the very cold nights outside roosting. Should we remove the outside roosts to encourage them to go inside at night or assume they'll go inside if they need too? It's been as low as 7 degrees in recent nights. I'm afraid they'll start laying ice-cubes!