I tried taking my Ball out twice; each time she would look around cautiously, then suddenly ball up tightly. It's the only time I've ever seen her live up to her breed name. Needless to say, being outside is something she seems to definitely not enjoy, so I don't do it anymore. She only gets to cruise around inside under supervision.

My boa, however, could care less where she is, as long as she gets the freedom to check out what she wants. She's perused my front yard (back when I lived in a house. we were off the street and had a very secluded yard) and seemed pretty happy. But still, I didn't do it often. Just as an occasional summertime treat.