Why Do Hamsters Bar Chew? ... Boredom - If there aren't enough toys to play with or chew on, a hamster may begin bar chewing due to boredom. Hamsters need mental and physical stimulation just like other pets and if they are isolated to a small, rectangular cage with nothing to do they could resort to this activity.

Is it normal for a hamster to bite the cage?

If they regularly gnaw at the bars, hamsters can damage or even break their teeth. The habit can also lead to mouth and facial injuries, often through a condition known as bar-rub. Metal bars are not good for a hamster's teeth - they're far too hard, and will push the teeth out of their normal alignment.

How do I get my hamster to stop chewing on his cage?

Carrot or apple work well, or a very thin smudge of peanut butter. A substitute can be wedged between the bars at her favorite chewing spot. A lab block, hamster-safe dog biscuit (should not contain garlic), tightly rolled cardboard, apple branch or a Popsicle stick work well, especially if they're anchored tightly.