I have cats. I buy cat little for them, usually made from clay. I had to look twice the other day at the pet store, though, when I saw cat litter made from corn kernels -- actual, edible corn. Here's the URL:
http://www.worldsbestcatlitter.com/safety.htm
This is what slays me. We pay farmers a subsidy to grow corn, so much per bushel, no matter how much they grow. So the oversupply in the U.S. market is so great that we now make the excess into cat litter.
I've just gotta shake my head at a world where some countries grow so much food -- too much food -- that they let their cats pee on the excess. Whereas some people in other countries go to bed hungry,and would probably be glad to take that "cat litter" and make some kind of meal out of it.