ink-free shredded paper
recycled paper litter
non-resinous wood shavings
Never use cat litter, pine or cedar chips as bedding for your rodent. The dust and aroma create respiratory irritations, and pine and cedar chips have been implicated as being toxic.
Dangerous Bedding Material
There are various types of fluffy cotton wool type bedding sold in pet shops for small animals and marked as "safe". Unfortunately there have been numerous cases where this type of bedding has caused injury, even death, to small animals.
This type of bedding does not dissolve in the stomach if eaten and can therefore cause a stomach blockage. Also the fine fibres have been known to get caught around a hamster's limb and tighten cause injury, even amputation to the limb. The bedding can also become stuck in the rodent's cheekpouch.
Normal clay or clumping cat litters can be harmful to rodents if ingested
As a general rule, any bedding used for rodents should dissolve if placed in water or a very weak acid solution and should break easily. This will ensure that if eaten by the rodent the bedding material simply dissolves in the stomach and if caught around a limb it is easily broken by the rodent.
Any bedding material that does not meet these criteria should not be used.