Catching your cats licking each other can evoke various emotional responses from “aw” to “ew”. So, what’s the deal with your cats treating each other like a fresh sardine-pop—why do cats groom each other and us?

With 30 to 50 percent of their day spent grooming themselves, cats are clearly skilled at self-care. Cats have a special tongue to thank for their cleanliness. Their tongues don’t actually resemble sandpaper, despite how rough they might feel. Covered in hook-like hollow hairs, cat’s tongues are more like a shampooing comb—amazing, right?

But, when it comes to grooming each other (and their humans), cat-to-cat cleaning serves a range of different purposes. Cats lick each other (and their humans) to communicate, show affection, and, sometimes, out of survival instinct. This communal grooming behavior is called allogrooming, and here’s why your cat does (or doesn’t!) allogroom their furry housemates.

1. Cats Groom To Show Their Bond

“With preferred individuals, cats demonstrate bonding with one another through allogrooming,” says Steve Dale, CABC, public pet speaker and author of Good Cat! And he emphasizes preferred individuals—a cat won’t allogroom any random cat.

“They have to be individuals who have a relationship—a special relationship,” Dale says. In outdoor colonies, this relationship is typically reserved for close family members. Littermates, and mothers and their kittens may have this bond, for example. Also, cats who have been together for an extended amount of time, (typically years not months) can show this level of connection.

If your cat gives or receives a bath from another cat, chances are they’re bonded, says Andrea Arden, pet training expert. “If two or more cats choose to be close to one another that suggests that they are comfortable with, and benefit from, each other’s company.”

2. Survival Instincts: Clean Cats Live Longer

Bonding isn’t the only reason cats groom each other—at least in outdoor colonies. Allogrooming is important for survival. Aiding in the removal of fleas, ticks, and other life-threatening parasites.

Indoor cats might allogroom, in part, because their survival instincts tell them to. But that drive is likely minimal—especially if your cat is up to date on flea preventatives. More likely, Dale says, indoor cats allogroom because “it’s social and a means of communicating mutual trust.”

3. Allogrooming Helps Other Cats Groom Unreachable Areas

“Cats don’t like to be dirty,” Dale says. And what better way to clean those hard-to-reach spots like the top of the head than a trusted feline friend?

Plus, just like cats love to be scratched on the top of their heads, on their cheeks, and under their chin, they love for their closest companions to groom those same places. Cats lick each other’s 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,” Arden explains.

4. Mother Cats Groom Their Kittens

Maternal allogrooming is one of life’s first experiences for a newborn kitten. Mama cat will immediately clean her young after they’re born, grooming to stimulate elimination and clean up after her little ones.

As kittens develop and learn to eliminate on their own, mom continues allogrooming behaviors. “While hygiene is one of the main underlying factors for mother cats to lick their kittens, maternal allogrooming also serves to support bonding, to provide comfort, and to teach them to groom themselves,” Arden says.

5. It Can Signal Health Problems

According to Dr. Louis DelGiudice, DVM, National Emergency Specialty Director at AmeriVet Veterinary Partners, a cat licking themselves excessively could signal skin inflammation or itchiness. Common causes include parasites like fleas or a food or contact allergen.

“Many cats form close attachments to their feline housemates and can be quite in tune with their emotional and physical state,” Arden says. Whether your cat is excessively grooming or not, other cats in the house could pick up on their change in health. “Other cats might spend more time in close proximity to them and groom them more frequently.”

According to Young-Williams Animal Center, it’s not true that a cat’s saliva has healing powers. Despite popular belief, a cat’s mouth is full of harmful bacteria (like all mouths!) that could cause an infection. Plus, those comb-like hairs on a cat’s tongue could easily reopen a healing wound. So, discourage your cat or other cats from licking wounds.

“Being aware of your cats’ baseline behavior to recognize any behavioral changes is an important part of identifying possible health issues that warrant contacting your veterinarian,” Arden adds.

6. Grooming Redirects Aggression

“Cats being cats, I suppose they’re dominant over humans,” Dale jokes. But “when cats allogroom people, they are not expressing dominance.” However, if you live in a multi-cat household as I do, then you might have noticed one cat always licking the other. So, do cats lick each other to show dominance?

“Cat-to-cat relationships are very complex,” Dale says. “It depends on context.”

Some sure-fire signs that your clowder (a group of cats) is struggling with hierarchical dominance include true aggression, marking territory, and blocking other cats from accessing the food bowl. Sure, household cats may allogroom to establish and maintain hierarchy, Arden says, but it’s more likely these cats are actually avoid serious conflicts. And allogrooming is to thank in these situations. Here’s how it works:

“A cat might lick another cat lower in hierarchy as a way of calming themselves. In addition to redirecting their aggression the allogrooming is possibly a bonding moment,” she explains. “But this does not mean that a lower-ranking cat is always on the receiving end of grooming.” As we said, cat-to-cat relationships are complex, and one interaction isn’t a tell-all sign of your clowder’s social life.