Cats are very clean animals. They groom themselves by licking their fur. The cat's tongue can act as a hairbrush and can clean and untangle a cat's fur. Still, owners may buy grooming products to help the cat take care of itself. After licking their fur, cats sometimes get hairballs. A hairball is a small amount of fur that is vomited up by animals when it becomes too big. This is quite normal. Owners brush their cats to try to prevent a lot of hairballs.