Here is my hamster Sargeant, hanging out with the cat. Sargeant sure loved his sleep but when he was awake, he would always be chewing on something. He chewed up a lot in his plastic cage so I had to put him into a wire cage. But he learned how to open it, by pushing as hard as he can with his chin on the door until he got it open. I had to buy another cage for him where he finally wasn't able to figure out how to escape. Unfortunatly Sarge died just before Christmas..