So I read somewhere that if rats even have slight draft in their cage they can get sick? My rat Bilbo (approx 6-7 weeks old) is kept outside during the day currently, in a sheltered cage up against the wall of my house. He has a sheltered lower story to his cage which has solid walls and a half roof. I take him inside during stormy/wet weather and during the night but I wondered if he could get sick from the slightest draft, like this thing said?