Plain old sand is always a natural option for kitty litter, but you can do one better by filling their pan with United Pet Group 10 lb. Corn Cob Natural Care Cat Litter. Made from biodegradable corn cobs, this finely ground material is virtually dust-free and uses natural enzymes to help control odor. * Made with gentle, natural corn fibers * Comes with odor control bio-enzymatic system * Lightweight and easy to carry * Proudly made in the USA * Perfect for cats and kittens