Cats are strange and mysterious creatures with more than a few secrets. From their nine lives (myth) to their astounding ability to land safely on their feet almost every time they jump or fall (real), cats are definitely savvy in some ways we mere humans are not. One of the strangest things about them is that small pocket in the side of their ear. If you’ve ever found yourself asking, ‘Why do cats have slits and pockets on their ears?’ we have good news. After exhaustive research, and more than a little fact-checking, we know the answer to one of the great cat mysteries, and we’re going to share it with you.
The story of domestic cats and all the mysteries they bring to our lives goes back thousands of years. Strangely, their success is almost certainly tied to that weird little pocket on their ears. At some point before we learned to write, these funny, furry little creatures looked at our struggling settlements and thought to themselves, ‘those guys need help with their pest problem, and I could use a few extra hours of sleep a day,’ (or something like that, it’s hard to tell with cats). That is how they came to adopt us. Not surprisingly, some of our ancestors in Egypt thought they were gods. After all, they certainly act like they run the world.
You read that right. We did not domesticate cats. In fact, they may not be genuinely tame at all. If anything, the process was nearly the opposite of what you might expect. Cats showed up in human settlements and offered their services as pest control in exchange for keeping the dogs at bay, and easier hunting. As if they needed to make their lives any simpler. Cats have always been magnificently successful hunters who spend most of their days sleeping in the sun.
We were only too glad to accept their beneficence because as useful as our domesticated wolves (dogs) are; they don’t quite keep up with felines when it comes to mousing, and catching bugs. As a result of this unspoken agreement, cats got easy pickings and adoration. Humans, on the other hand, got to keep a whole lot more of their food, and fewer bugs and rats spreading sickness. In short, it was a good deal, and it was their idea.
That isn’t the strangest thing cats have done in the last few millennia, but it is probably how the first people came to notice that weird little slit and pocket cats have on their ears. Though it would be centuries before we finally began to learn what it was for, cats have been using that pocket to help themselves, and by extension us, for a very long time.
A Cats’ Outer Ear
To better understand what that funky little feature has to do with the way cats domesticated us, it helps to take a good look at how cats’ ears work. To begin with, let’s talk about the pinna. The outer triangle of a cat’s ear (the pinna) is part of what allows them to hear as well as they do. The fuzzy triangle we coo over works perfectly to funnel sound into their waiting sensors. A Cat’s pinna can rotate a hundred and eighty degrees using over thirty different muscles. While that isn’t quite as impressive as an owl turning it’s had two hundred and seventy degrees, it’s still a whole lot further than most creatures can move an ear. We humans struggle just to make ours wiggle a little for a laugh at parties.
The little slit that’s a part of the Henry’s Pocket (yes, it has a name) may give cats some added mobility and range when turning their ears. This incredible flexibility helps them tune in and locate sounds. They are auditory experts who can pick up both higher and lower frequencies than you or your dogs. So if you’ve ever wondered whether your cat can hear a dog whistle, the answer is yes. If you wonder why felines don’t respond, it’s because they’re cats, and they don’t have to listen to you if they don’t feel like it.
Cats aren’t the only creatures who possess this unique feature. A handful of dog breeds, typically those with upright ears like Boston Terriers, Chihuahuas, and Corgis, share the Henry’s Pouch. It can also be found on bats and fennec foxes. Naturally, the mystery of its purpose remains ubiquitous regardless of which species you’re looking at. Though it is noteworthy that all these species have unusually good hearing and excessively mobile ears.
Deeper Insight Into Cat Hearing
The Henry’s Pocket, or that funky little pouch you’ve been wondering about, is known scientifically as a cutaneous marginal pouch. It probably serves cats by picking up the most minute and distant sounds and channeling them down into the ear canal. Unfortunately, at the moment, this is still just a hypothesis and hasn’t yet been proven. Sorry, we know we said we’d solve the mystery, but cats are far stranger than our science can fully explain.
Unlike humans with our less-infection-prone horizontal ear canals, cats, along with dogs and a few other creatures, have ear canals that go straight down into their heads. This is part of why they hear better than we do. In fact, they can pinpoint the specific direction and distance of a squeak or rustle to within 5 degrees according to Canidae. The pinna and probably Henry’s Pocket send vibrations (aka sound) down that canal to the bones in the middle ear, which in turn sends the message along to the inner ear where they’re picked up and translated to the cats’ brain. This strange process is very similar to the way humans hear, but cats do it more efficiently. A big part of that is likely thanks to the cutaneous marginal pouch.
In short, the reason cats are so successful at hunting isn’t necessarily their speed or stealth, though they have plenty of that. It’s not even their incredible muscles or all those highly effective claws. Instead, it’s the fact that prey can’t hide from them because wherever it runs or squirrels itself away, a cat can hear it move, breathe, and maybe even detect the sound of its frantic heartbeat. It is this seemingly magical ability to root out pests that allowed the first cats to get easy meals out of the humans who, by their standards, must seem almost deaf. Better yet, we thanked them for it, and eventually started letting them sleep by our fires and drink our milk, not that they needed more incentive to tolerate us.
A Note for People with Cats
The Henry’s Pocket is a perfect breeding ground for mites, fungal infections, and other ear problems. Next time you’re petting those pretty pinna, give the cutaneous marginal pouch an extra close look. Cats are more prone to aural (ear) problems than we are, so always pay close attention if your pet is rubbing or scratching at their ears more than usual.
Humans got to the top of the food chain by working our big brains, learning teamwork, and the secrets of fire. Housecats got there by looking at what we weren’t very good at and offering us a hand because they were already incredibly successful apex predators. It was probably easier to lend us their ears, and their Henry’s Pockets, than it is to work for a living. No con in history, or prehistory, has ever been more successful. We still love and spoil them for it to this day. Next time your cat rotates its ears to ignore you, or warn you about a mood swing, take a moment to admire that strange little pocket and consider all the history that might not have been possible without it.