Not all cats will use a litter box. Some probably don’t use it out of spite to their human owners, but others may simply have no idea that the litter box is where they’re supposed to go to the bathroom and not on the expensive carpeting in the living room.
Several ideas for getting a cat to use a litter box include:
- Putting it in an isolated area
- Rewarding the cat each time it uses the litter box
- Using different litter that may not have perfume scents that the cat may dislike
Of course the easiest solution is to just let the cat go to the bathroom everywhere so you can have the fun task of cleaning it up, which is what most cats would probably prefer anyway.