We have had a homeless kitten move into our backyard. She hangs around the outside of the henhouse at night, feasting on any mice that make the mistake of coming near that henhouse. She's turned out to be a good cat, overall. She mostly disappears during the daytime, but comes back every night for warm cat chow and wayward mice. I don't know where she is hiding, other than it is some well secluded place behind the henhouse. I built her a little cave out of bales of pine shavings -- it is comfortable and extremely well insulated. But she seems like she is afraid to even go into the little cave, and chooses instead to hide herself someplace else that we haven't found yet. Nights like this are bad enough -- it's about 30 degrees outside right now. She's hidden herself somewhere behind the henhouse, but comes out when I bring warm turkey soup and cat chow for her. But what do we do when it gets even colder? How cold can it get and a little cat without a real shelter make it? We cannot bring her into the house. Our house is small, and there I have both a wife, a little child and another cat living in here already. The two cats fight anytime they see each other. Besides, there is just no room for her inside the warm house, even just for a few nights. And she won't use the warm little cave I built her near the henhouse. At what temp MUST we figure out a place for her, and what do we do if she just cannot come inside? I do have the big dog pen that I sometimes put baby chicks in. I have thought about locking her up in there if the temps get brutal enough, and putting her in the shed where we keep our freezer. That shed has a small utility heater in it (the kind that is sometimes used in barns), and the heater is programmed to come on and go off based on room temperature. We could put food, water, a cat toy or two and a battery powered radio to keep her company, and check on her periodically during the night. I don't know -- what do you all recommend?