No pine, no cedar, no corncob.

Cedar and pine both contain oils called phenols, which irritate small animals lungs, giving them respiratory problems. When it comes to kiln dried pine I find that to be much safer than regular pine, because there is absolutely no dust and the phenols are removed, there is hardly any smell to kiln dried pine. Corncob gets moldy and can harbor bacteria. Some small animals may try to eat the corncob bedding which isn't good, especially if it is moldy.

I personally use aspen bedding, and I just picked up a bag of Kaytee Soft-Sorbent, which is exactly like white carefresh except about $200 cheaper.

Ground walnut shells, rabbit pellets, aspen, Carefresh, Yesterdays News, Crown Animal Bedding, Bio-Flush, Eco-Bedding, and Critter Country are some good alternatives to cedar and pine bedding.

Kaytee Soft-Sorbent