It's best to clean the litter box once a day. Cats will defecate in the litter box every day, and it's best not to let their excrement stay there for too long. Firstly, cats don't like to use a dirty litter box, and secondly, excrement can breed bacteria, leading to air pollution and bacterial infections in the cat. Therefore, it's ideal to clean the litter box once or twice a day. 
Consequences of not cleaning cat litter:
1. It will breed bacteria. If cat excrement is not cleaned in the litter box for a long time, a large number of bacteria will grow, and parasites may also appear, which is very unhygienic.
2. It can cause illness in cats. Cats that defecate in unsanitary litter boxes are more susceptible to bacterial and parasitic infections, leading to urinary tract diseases and other ailments.
3. It can cause cats to urinate indiscriminately. Cats are very clean animals; they can be quite fastidious and dislike defecating in a dirty litter box, so they will look for other suitable places to relieve themselves.
4. It can affect a cat's mood. If a cat doesn't have a clean place to relieve itself, or can't find a more suitable place, it will often hold its urine, which can cause the cat to become anxious and irritable.
5. It will affect the owner's life. If the litter box is not cleaned for a long time, the odor will be very strong, and the dry litter dust will float in the air, which will have a great impact on the owner's life.
