OK my hammy seems to be going through the same thing! He is just so active! I have him running around the bath for half an hour each night, then back in his cage for a while, then 25 mins running in his ball and he still runs around chewing the bars in his cage.
But then I thought, well he doesn't really have a whole lot to do in his cage, he has a tall cage, with platforms and tubes, and a wheel, but really, nothing interesting. So I've bought him a bigger cage with more floor space and I'm gonna fill it with things to do