Cats lick each other's fur for many purposes. They are mainly used to mark their own scent, play when they are bored, and clean dust and parasites from their fur. Generally speaking, when cats lick each other's fur, they treat it as a family member. In this way, cats can mark their own tastes so that they can better distinguish each other. Licking each other's fur can also make everyone taste the same. Cats will also lick their fur when they are bored. One is to kill time, and the other is to clean them in place. Others can clean the places that the cat cannot lick by itself, such as the face, top of the head, and ears.