My babies are in a puppy exercise pen thing in the backyard during the summer staked down so they can't squirm under it. Half is shaded and half is sunny at any given time of day and they like to hide under a terra cotta pot broken in half. And since I'm not letting them hibernate until they're older they live in a big ferret cage (cat and dog proof) inside with plants during the winter. My adults live in a decent portion of the backyard bordered by the house, the privacy fence, and the deck. They have shaded areas, sunny areas, lots of bushes to hide in and a shallow "pond" 2x2' (only about 2 inches deep) where like to just sit in the water and enjoy the sun. I've seen lots of varieties of enclosures but the key is to have sunny and shaded areas, places for them to hide, and escape-proof! They are masters of escape and can climb some fences and steps fairly easily! And they'll dig under things too!