A dwarf hamster's teeth will grow constantly throughout its life time so the opportunity to chew on hard things is important. Dog biscuits, lab blocks, wood chews, and calcium chews (made specially for hamsters, do not give them a calcium tablet) can be safe objects for chewing. Choose wood carefully because some can be toxic or have toxic chemicals added. If you do not give a hamster enough things to chew, it will chew on it's cage bars (if in a wire cage) and anything else it can get hold of, in an attempt to wear down its teeth.