Bedding: Aspen - Is a hard wood and a good choice for litter. Because Aspen can be home to mites it is important to freeze it before placing in the cage. It is also light and can be messy if your rats like to dig around in it. CareFresh - Made from paper pulp absorbs well and many people are quite happy with it. It can get a bad smell when wet so daily spot cleaning is recommended. Cat Litter - ( the typical clay kind) - This is way to dusty to be used in the bottom of the cage. Cedar- This is not a good bedding choice for your ratties. The phenols found in it, as well as other soft woods, are toxic to all rodents. Cloth - T-shirts and fleece can be changed out daily, washed, and then reused. Since rats like to chew holes in them, once they need to be sent to t-shirt heaven, purchasing more at thrift stores is a great money saver. Do not use material that unravels easily especially with babies and young rats, they could easily lose a limb or worse if a thread gets wrapped around a leg, a neck etc. Corn Cob - It becomes moldy quickly when wet, so must be changed often if used. Paper Pellets such as Yesterdays News and Good Mews- This is made of recycled paper and can be found in the cat litter section. It is very absorbant and keeps odor down well with daily spot cleaning. Pine - Same as Cedar Rabbit Food - Rats won't eat it, it is great at odor control and is inexpensive. It is heavy so is not thrown out by digging rats. You can buy 50 lb bags at the feed store for a very reasonable price. A bag that size is enough for approximately 12 to 14 changes for a 30" x 18" cage pan. Smells of freshly mowed grass. Shredded paper - Shredded paper can be used on the bottom of the cage. Clean soiled areas daily. If using newspaper be sure the ink used is non-toxic. *Bold Text - recommended *Regular text - I do not recommend