Hamster Fact: Bar Chewing, its a common problem with hamsters. Since they are rodents, their teeth continue to grow and they need to gnaw on hard surfaced to wear their teeth down. Some hamsters resort to chewing the bars of their cage. Not only is it annoying to the owner, but could be bad for the hamster too. The hamster may break a tooth and more seriously could sustain brain damage due to the constant rattling of their heads as they chew. One way of fixing the problem is to get a glass aquarium for the hamster therefore there are no bars to chew. The other thing is to supply them with lots of toys and things to chew on so they wont be so focused on the bars as snack. Miss S is a bar chewer, she has lots of toys to chew on and gets plenty of paper toilet rolls and cardboard to pulverize. When she chews her bars I think she wants attention and wants to come out of the cage, I then take her out so  she can explore. She has me well trained. :)