This prevents many litter box problems. However, if a cat has developed a preference for another material or location, the cat should be confined to a small territory with appropriate litter material until a new habit is established. This can take a couple of weeks. As a group, cats prefer to use deep, unscented, clean, sand litter. Some individual cats prefer a hooded litter pan and some don't like plastic litter liners.
Some cats prefer to defecate and urinate in separate places requiring two pans.
Some cats will not share a litter pan with another cat. The solution is often more litter boxes, filled deeply and cleaned often, kept in a location that is easy to get to but not disturbed during use. Moving a litter pan can also cause problems for cats. Cats may continue to urinate or defecate on the floor in the pan's original location. In experiments in which soiled carpets were turned 180 degrees, cats did NOT return to the soiled spot on the carpet but instead continued to use the same spot relative to the room.