Didn't hibernate my four this year as hadn't had them long enough to know whether or not they were healthy and putting on weight. they spent the winter indoors but are now enjoying their new enclosure during the day - still bring them in at night though. Have had so much fun building the ensurfor them, it's huge with a solarium, tortie friendly plants, hills and logs etc plus all sorts of tortie friendly plants - have also filled in an old pond with gravel which catches just the right amount of rainwater to allow them to have a drink and a paddle plus a drinking staon. Great pets - Love um