Cats bury their waste in a litter tray to hide the odor from predators. This is a survival instinct. When they use the toilet instead of the litter tray the water in the pan hides the odor more effectively and the cat is satisfied. The Litter Kwitter leads the cat through three stages of behavior modification to teach the cat how to balance on the toilet, how to aim correctly into the pan and finally how to go without the need for litter.