Some cats will dig a small hole first, and most will cover their urine or feces with litter after they have evacuated. A layer of baking soda on the bottom helps control odor. It's best to stick to one good brand of litter. Switching brands often can make some cats refuse to use their litter boxes. Avoid buying litter that contains a lot of fine dust, which could cause problems for the cat.
Some litter boxes have a removable cover.
A covered litter box helps stop the cat from pawing the litter out of the tray. It is important to keep the litter box clean, because accumulated urine can make the interior of a covered litter box irritating for the cat to enter. Cats are fastidious creatures and can become unhousebroken if the litter tray is dirty, or if they are suffering from a bladder infection, intestinal upset, or emotional disturbance. A dirty litter box is a major reason why cats become unhousebroken. You can retrain cats to use their litter boxes, but first it is essential to taken an unhousebroken cat to the veterinarian to check the cat for a number of physical ailments and emotional stresses that can make cats unhousebroken.