There are SO many cage beddings available for use. They range from very inexpensive to VERY expensive, depending on how many cages you have.
Pine and cedar should NOT be used as bedding. Yes, they are very cheap. They also contain aromatic hydrocarbons - this is what gives them their distinctive scents. Rats have very sensitive respiratory systems, and being kept on these beddings only irritates their lungs. While it may smell good to a pet owner, your rats aren't having fun! There is also evidence that it has less visible effects such as causing liver or kidney damage. With all the other types of available bedding, why take any chances?
The second type of bedding to avoid is any sort of clumping cat litters. They are usually clay based, and dusty. The dust will affect your rat's respiratory system, and since rats groom themselves very often, they will ingest the clay dust, which can clump inside of them! Surgery to remove a blockage is not cheap, why not buy an appropriate bedding right from the first?
