Cats need to clean themselves.
After a cat defecates, there will always be some feces residue around its anus. Some cats are very clever and will rub themselves off on carpets, dirty clothes, or scraps of cloth. Cat owners can carefully check the items their cat has rubbed against to see if there is any feces residue. Remember to clean them afterwards to prevent the growth of bacteria and viruses. 
When a kitten reaches 3 months old, if the owner hasn't dewormed it and the environment isn't very clean, it may rub its anus due to parasite irritation. The owner can check in two ways: first, examine the kitten's anus for white, granular worm eggs, and check the feces for eggs or adult worms; second, take the kitten to a veterinary clinic for a fecal examination to confirm the situation. If confirmed, administer the appropriate deworming medication.
Possible anal gland inflammationCats have anal glands on either side of their anus. Cats kept indoors for extended periods may experience reduced secretion of anal gland fluid due to environmental factors, leading to inflammation of the anal glands over time. A cat may be rubbing its bottom because of inflamed anal glands. Owners can check their cat's anus for any protrusions; if present, they can try to express the protrusions themselves or seek help from an experienced person.
