I will get him back inI do see the idea, but it's still recommended to have a hamster in a securely closed enclosure overnight. I would worry about them having that kind of free access overnight if I wasn't there to keep an eye on things. On the other hand if the enclosure was inside a secure playpen, then maybe but a playpen can still be scaled somehow. As I say, Tino managed to escape a bucket ............. Also if they do get on the loose, they can keep hiding and it's a worry if it goes on for days and you don't know where they are. One owner eventually found her hamster trapped behind a piece of furniture, where the hamster had died trying to get out again.