If you have more than one cat, you should have a minimum of one box per cat plus one extra. Keep the litterboxes in different areas of your home. If you live in a multiple-cat household, it is possible for one cat to prevent others from approaching the litterboxes because they are located within its territory. Spreading the boxes out will make it difficult for the territorial cat to patrol them simultaneously. Multiple boxes also increase the likelihood of a cat having at least one clean box to eliminate in if all the boxes are scooped daily.