Cats lick and groom each other for various reasons, including communication, bonding, and survival instinct. This behavior is called allogrooming, and it is a normal part of feline behavior. Here are some reasons why cats lick each other:

• Communication: Cats use grooming to express their relationship to other cats between each other. For example, in a group of wild cats, some may groom others to show they are closer than other members of the same colony. In a home setting, your cats may be telling each other that they trust and respect one another. They might also be communicating this to you.

• Bonding: Cats also groom each other because they are bonded with each other. Littermates and cats who have lived around each other for most of their lives may treat each other with this type of respect and admiration, and they may groom each other to show their bond outwardly.

• Survival Instinct: Cats lick each others heads and other facial features because all these spots have scent glands that release pheromones. These pheromones are chemicals that provide information for communication with other cats. This is part of why much of allogrooming is focused on these areas of the body. Cats also lick each other to create a shared scent thats unique to the group. Because cats use scent to identify friend from foe, this group scent is incredibly important for recognition.

• Hygiene: Cats groom themselves to keep clean, and they may groom each other to help with hard-to-reach spots. However, excessive licking could signal skin inflammation or itchiness, which could be caused by parasites like fleas or a food or contact allergen.

Its important to note that sometimes cats may groom each other aggressively, which could be a dominance act. However, if the cats are generally friendly and have relaxed posture together and relax easily after their grooming or play sessions, theres probably nothing to worry about.