My chin Zidane does that and chews on his bars. Seems to have this idea in his head that if he keeps trying he can escape. I think he mainly does it for attention and to hint that he wants out. Of course he has to learn that he can't always get what he wants... at least until he twists his little paw around my finger just so. Usually I just give him a stick to appease him until I am better suited to give into his chinchilla wants.
omg i had the same issues and freaked over it. but they like to do that for some reason and sometimes my babies just lay there and nose it out in the open. I feel like they smell something LOL
but usually is when they want to get let out. its ilke they know when its their time to be able to COME out and play haah