I let my sulcata, Ozzy run around the yard for about 5 hours after I get home from school, and he never has tried to get out. Of course, I check on him once or twice a day, though. Where are you located? I have a friend in Seminole, Florida, Ken, who owns a pet store called Pet Biz-Ar, and he has two large sulcatas, a male and female that freeroam his yard all day, have no pen, and they never try to dig. If you're in Florida, you can call him at 1-727-398-1700.