We often think that cats groom themselves. However, cats lick themselves. They ingest their loose hairs which can cause health problems related to hairballs. Cats also produce oils on their skin. With long haired cats, these oils build up causing tangles in the coat especially behind the ears, base of tail, as well as under the arms and legs. To truly clean a cat, you must remove dead skin, hair, spit, urine, fleas and stuck on feces.