Watching cats groom each other can be so relaxing, right? Does it also make you wonder why they’re doing that?
Cats usually groom each other for these reasons:
- Hygiene – simply to help each other keep those coasts shiny and clean.
- Social bonding – the closer you are to someone, the more comfortable you feel with them.
- Aggression – yes, aggression. That’s the surprising reason we walk about in the title. Keep reading to see why aggression is sometimes expressed through social grooming.
“Why do cats groom each other?” is an excellent question that has more than one possible answer. We went on a research adventure, seeking actual scientific studies that looked into the question.
Today we bring you some of the fascinating science-based answers! Read on to become smarter cat owners. Because understanding what makes our cats tick helps us make sure they’re healthy and happy!
First, some definitions.
Allogrooming – Not just cats!
Grooming is when a cat licks his/her own coat. Some people call this behavior washing, cleaning or just licking their fur.
When grooming, cats often move on to lick whoever is next to them. This is often another cat, but it could also be a dog or any other animal. It could also be you – the human!
Then there’s Allogrooming:
Allogrooming is the fancy scientific word for social grooming. In other words, that’s when an individual of a species grooms another for social reasons. Allogrooming can be mutual grooming, where both individuals groom each other in a reciprocal way.
You might be wondering:
Which other species engage in social grooming?
Lots and lots of species! Did you know that even bees groom each other?
Some birds groom each other too, as do many mammals. Horses, bats, monkeys… you name it! They all engage in allogrooming from time to time.
Humans do too –
Back to cats:
Felines – large and small – are known to be clean animals that take great care of their personal hygiene. All felines also engage in mutual grooming – at least when they have a social setting.
Now, some big cats are loners. That doesn’t mean they never engage in social grooming. They do – in the relatively short period of their lives when they have positive social interactions with other members of the species. First and foremost, a mother with her kittens, but also mating couples.
But what about domestic cats?
If you own more than one cat, there’s a good chance that you witness mutual grooming quite often. It really is sweet to behold, isn’t it?
You might be wondering:
“But my cats don’t groom each other! Is there something wrong with them?”
Nope. Not all cats that live together will groom each other. Why? Well, let’s look at why cats groom each other and try to figure out the answer.
Finally, let’s look at the possible reasons for actual mutual grooming, or allogrooming.
We’re going to discuss origins: your cat’s first experience of social grooming. Then go over the three explanations of social grooming in adult cats:
- Social bonding
(Yes, aggression! Sounds strange but we have the science to back it up!)
Your cat’s first experience of social grooming
Where does this act of social grooming come from? What are its origins?
Grooming interactions between cats can be traced back to a mother cat’s instinct to groom her kittens.
If you’ve ever seen a cat give birth, you know that the mother cat begins intensively licking the kittens as soon as they are born. She does so while siblings are still in the process of being born and doesn’t wait until the birth is over. She licks – and eats – the blood, placentas and anything else which was secreted along with the kittens. Sounds gross? It is to us humans, but in nature most female mammals do exactly the same thing.
For several reasons:
1. Eating the gross stuff provides her body with important nutrients, especially since she probably won’t be able to go out and hunt for food for several days.
2. The mother cat literally washes and cleans her kittens this way. Remains of dead body tissues are more than just disgusting. They can rot away and put the kitten at risk for infections from that huge amount of bacteria breaking them apart. Any “leftovers” will soon stink – again, bacteria! – exposing the kittens to potential predators who may pick up the stench.
3. Licking a kitten’s tummy and behind stimulates their bodies to pee and poo. If the mother cat doesn’t lick them – the kittens will soon become constipated. That’s why rescuers who care for orphaned kittens need to gently massage the same areas. Read more on rescuing orphan kittens here.
4. There’s one more thing – and it’s crucial for the purpose of this article – this is how the mother cat bonds with the kittens. And as anyone who’s ever watched the interaction can attest to – kittens become calmer once they feel their mother’s tongue.
And now that we know all that, let’s look at the three explanations for mutual grooming behaviors in cats.
1. The cats are just cleaning each other… or are they?
While self-grooming is an obviously hygienic behavior, there is actually a debate about whether that is a motivation when grooming each other as well. After all, cats who don’t share their household with other cats do just fine with self-grooming.
The head and neck are areas of the cat that cannot be easily reached. Any cat owner has likely noticed that cats cannot lick these areas directly, but our nifty kitties have found a solution: They will wet their paws and use them to clean their heads and necks!
Could it be that the help of a feline friend has some benefits in the hygiene department? Maybe cats appreciate having another cat help with their washing and grooming routine? It’s certainly possible! No one knows for sure, and as we said, clearly cats can take care of their grooming needs on their own, too.
2. Grooming and Social Bonding
In 2004, the Journal of Feline Medicine and Surgery published a paper that examined how cats organize themselves socially. Long thought to be solitary, independent creatures, research has shown that – under the right circumstances – domestic cats instead prefer to gather in social groups!
This is obvious for anyone who has encountered a feral colony near their home. The availability of a central food source clearly determines whether cats will choose to create a colony. When food sources are more scattered and limited, cats tend to spread out more and keep to themselves.
When we keep several cats together inside our home, a similar process takes place. The cats develop social relationships including hierarchies. They may not always get along, but they certainly recognize each other as individuals and establish a sort of “pecking order”.
So, what about grooming each other?
According to the study, cats would actively seek out grooming from others they chose to more closely associate with. A cat wanting to be groomed by another would approach the target cat and flex its neck, encouraging the other cat to groom him there.
Those who were groomed without actively seeking it still cooperated, moving their heads and chins to allow further access to the groomer. These cats would also display reactions of enjoyment, such as purring, while being groomed. This grooming was accompanied by other friendly signals such as holding the tail vertical to the ground, rubbing their tails against one another, or even curling their tails together.
In fact, cats were most likely to engage in grooming behaviors when they both expressed these friendly gestures in their interactions. The grooming was sometimes reciprocated so that both parties took turns receiving the attention, but not always.
In 2013, another study came out supporting this explanation. This time scientists observed lions in captivity and concluded that head rubbing and licking – i.e. allogrooming – reinforced social bonds between the members of the pride.
Didn’t we mention aggression and dominance as a possible explanation? Well, we did, and it’s time to look into that aspect of mutual grooming.
Aggression and Dominance in Mutual Grooming
Ok, so we’re not talking about direct blatant aggression, obviously. However, observe allogrooming in cats closely –
If you’re very in tune to feline body language you may just be able to pick up on the tension there.
What? Aggression? But they seem to be relaxed and happy!
They are. But hear us out about the research that backs up this claim.
In 1998, a scientist by the name of Ruud van den Bos conducted a study about feline behavior that focused on allogrooming. Surprisingly, Van den Bos discovered a link between this grooming behavior and aggression.
When looking at social grooming, Van den Bos noticed that the dominant cats tended to groom the submissive cats. He studied their body language, as well, and found that the groomer would take on a more dominant posture during the grooming, such as standing or sitting up, while the one being groomed would be lying down or crouched.
This seemed to enforce the power difference within the pair.
But wait – there’s more:
In 35% of these situations, the grooming turned into a form of aggression. This aggressive behavior was, again, instigated by the more dominant of the pair.
The scientist came to the conclusion that the grooming was an additional way to establish dominance in the relationship between cats. On a gentler note, the grooming could instead be a means to express affection towards a subordinate. Either way, the behavior seems to reinforce the already established hierarchy between the grooming pair and redirect otherwise aggressive tensions between them.
What can we learn from all of this?
Knowing why cats groom each other can help us in two ways –
1. Understanding the relationship between cats in a multi-cat household.
2. Figuring out what cats think about us petting them.
If you own more than one cat:
Let the cats be and understand that they have their own social order that you can’t – and shouldn’t try to – control.
When you see your kitties grooming each other, be aware of the tension. Try to stay out of it and don’t be surprised if the activity ends with one of the cats, well, not so happy about the whole thing.
When petting your cat:
Remember that as much as your cat enjoys being petted, he or she also may see this act as involving some amount of indirect aggression. Be attentive to your cat’s body language and stop the interaction if your cat stops purring, becomes tense and begins to twitch the tip of it’s tail.
What about your cats?
Do your cats groom each other? What do you think is their motivation? Tell us in a comment to this article! And remember, if you have any questions about any behavior problems or anything cat-related, please let us know in the cat forums.