If your cute pet hamster has an inclination for chewing on the bars of his cage, do not be alarmed. The behavior, "bar biting," is by no means uncommon in the species. Since hamster teeth are perpetually growing, the little guys are gnaw-happy creatures.
Teeth Growth
A hamster's little chompers are constantly growing. Because of that, he'll frequently need to keep them in effective condition. By chewing on things, whether cage bars or anything else in his vicinity, a hamster is essentially honing his teeth to maximum benefit.
Enjoyment
Cage-chewing by hamsters has more than just a practical purpose. Some hammies take to chewing bars as a means of letting off steam and excess energy, according to Martha Boden of the Small Animal Channel. Some hamsters find the activity fun and enjoyable. In some situations, hamsters aren't aware they're chewing on anything -- because they're sound asleep as they do it. Some hammies start chewing bars because they're simply mimicking another hamster's actions. Hamsters may find the sound of gnawing on the cage bars pleasant or comforting. In many cases, cage chewing is a simple phase in hammies -- one that they grow out of in a span of six months or so.
Attention
A hamster may chew on his cage as a tactic for gaining attention due to pure boredom. If you have reason to think that this may be the case with your hammie, avoid rewarding him with playtime or petting sessions after he partakes in the behavior.
Items for Chewing
Prevent or minimize your hamster's cage-chewing inclinations by making sure that he always has access to plenty of toys or things that are safe for him to chew on, whether soft wooden chews, untreated wood, apple branches, small spoons made out of stainless steel or doggie biscuits. With other exciting chewing options, you may just stop your fluff ball from creating a massive and conspicuous hole smack dab in the center of his cage -- not bad at all.