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.