I'm pretty new to chickens. My three hens just started laying about a week ago now. The problem: My hens stopped coming in at night two nights ago - they are roosting in the dirt in their run instead, and I have to lift them into their coop. All the reading I have done suggests that this is from mites, but are mites really an issue in the dead of winter? It has been in the single digits here in MN lately. I am going to treat for mites tomorrow regardless, but I was just wondering if anyone had any other ideas of what it might be. Thanks for your help!