The real reason why cats purr and other feline facts

Cats, as the old saying goes, were once worshiped as gods and have never allowed the world to forget it. And why not? They're adorable, and who cares if they show a little sociopathic behavior every so often? Cuteness will get you out of a lot, but their standoffish nature and refusal to participate in behavioral studies (like their canine counterparts often do) means that we know surprisingly little about what's going on inside a kitty's mind. We do think that there's quite a lot happening in there, though, because they're just fascinating little heart-stealers. Here's why cats purr, along with other fun feline facts.

They're not actually domesticated -- they just let us think they are

No one's sure when cats first moved into our homes and our hearts, but the most commonly repeated trivia tidbit is that it happened in ancient Egypt around 4,000 years ago. There's other evidence that suggests it happened well before that, with remains of a human and cat buried together dating back 9,500 years. Cats in China were keeping homes rat-and-mouse-free (and sharing leftovers) around 5,300 years ago, so no one's exactly sure when the mysterious cat showed up and volunteered their services, and we're pretty sure that's how they plan on keeping it.

By comparison, dogs have been at our sides for around 40,000 years, and over those years we've selectively bred dogs to fill certain roles, from hunting and herding to sitting in purses. Cats, on the other hand? They're … cats. Sure, there's breeds of cats, but they're more or less cat-shaped. There aren't cats that specialize in herding or mousing or … well, to be fair, they're all specialists in being gods and goddesses.

When scientists took an up-close-and-personal look at their DNA, they found there's an incredibly good reason for this: they're pretty much not domesticated, at least, on a genetic level. Sure, there's the troll that says, "Clearly, they're domesticated, I'm not letting a filthy wild animal in my house." You'd be at least partially wrong, Troll. Genetically, our domestic housecat still has most of their DNA in common with their wild cousins, and unlike dogs (who have gotten rid of most of the unsavory behavior of wolves), cats have kept their wild instincts, too. Just ask anyone who's walked outside to enjoy a nice, warm spring day and stepped in disemboweled rodent.

Cats have almost mastered language, and they only speak to humans

We know you talk to your cat, and we know she talks back. (You don't? You're a heathen or a liar.) It turns out that language is another way cats display the brilliance they all know they possess, and we take for granted. Cats have a whole bunch of ways to communicate with us, and it's up to humans to pay enough attention to facial and body cues, like "crazy face" and "STFU ears," to be able to understand what they're saying.

They've also developed a super-top-secret language that they use only to communicate with humans: meowing. Cats that live together don't usually meow or talk to each other, and studies of feral cat colonies find that cats in only-feline company are pretty silent. It's only humans that they meow to and, if you pay any attention to your cat at all, you can probably tell what they're saying. Things like, "Put those opposable thumbs to good use and open the cat food now, Human!" sound pretty different from something that means, "Please sit and give me cuddles, and I will allow you to bask in my sleepy, adorable glory."

In 2003, Cornell University researchers tested whether or not we could understand our cats or if we were taking environmental cues to figure out what they're saying, and they had people listen to recordings of cats and try to tell what it was they were saying. They could, but only when the sounds were coming from their own cat. That implies that we shouldn't worry too much, because there's not some universal cat-language that they're teaching us. They are, however, each teaching us their own commands, which might be even more worrying? That's strictly a skill that's been developed by domestic cats, and we tend to interpret wild cats as sounding just angry, no matter what they're saying. The moral of the story is: your cat has learned how to sweet-talk you to get what he wants.

Your cat might have an allergy to humans

You know that guy: the one who claims that he can't have a cat or be near yours because he has an allergy. He says it like it's such a massive moral sacrifice too, right? It turns out that he might be the cause of allergies in cats, too, and if you ask us? That's a bigger offense.

It's estimated that about 1 in every 200 cats suffers from a cat version of asthma. It's a lot like human asthma, and essentially leads to breathing issues and coughing. The biggest cause? People. Human dandruff is cited as a major cause of feline asthma, along with other irritants that humans bring into their homes, like cigarette smoke. If you're a smoker and your cat coughs a lot, or sounds wheezy? Congratulations, you're suffocating him.

That's not an exaggeration, either. Some cats can have such a powerful allergic reaction to humans (and their disgusting habits), and they have to fight to breathe so much, they could suffer collapsed lungs or even broken ribs. Antibiotics and anti-inflammatories have been shown to help, and asthmatic cats can usually have their conditions managed, even though vets consider it incurable. So, be a decent human being and quit smoking.

Why some cats are catnip junkies

Do you ever feel like a crack dealer when your cat sees you getting out the catnip? For about 50% of the cat population, catnip is like happiness in herbal form, while the other half (and kittens) have no response to it whatsoever. What gives?

The gene that makes cats sensitive to catnip is hereditary, and it's an inherited response to a chemical called nepetalactone. The scent bonds to receptors in the cat's nasal passages, which then stimulate the sensory receptors in the brain. If your cat's acting like they're on a complete sensory overload, that's because they absolutely are. And they're loving it. Some cats have a … specific set of responses they exhibit when they're exposed to catnip, and it's akin to a cat in heat. That's because the senses that are being overloaded are the same ones triggered by cat pheromones, so when you give your cat some of the nip? Give them some alone time, too. They deserve it, and expect it.

Their brains have 90% in common with ours

It's an age-old argument: who's smarter, cats or dogs? (People aren't a choice in the equation, because cats and dogs are both definitely smarter than most people.) It turns out that, on a biological level, cats might have a slight edge on dogs, but we hope you won't tell them that. Dogs will never live it down.

With the wonders of modern science, researchers have been able to measure the number of neurons present in the part of cat and dog brains responsible for things like problem-solving and information processing. Cats have a staggering 300 million neurons, while dogs only have 160 million. Sorry, pups.

While that means that cats are going to be quicker at some things than dogs, what about comparing them to humans? Part of human's processing power comes from the folds that are on the surface of our brains. The more wrinkles there are, the larger the surface area and, in turn, the more processing power the brain has. That's where the 90% number comes in, and it turns out that cat brains are wrinkled like ours, so much so that they're 90% similar. They also have large and complex cerebral structures, which governs decision-making, memory, advance planning, and reasoning skills. Their similar brains mean that there's a lot going on in there, and if they found time and motivation to care, they could outsmart circles around Pupper. So the next time you suspect Kitty is plotting to install himself as the world's next great supervillain, he just might be.

Girls are right-handed, boys are left-handed

Right. Since we all need a little recovery time after realizing Snuggles probably wants to conquer the world, here's a fun bit of trivia that's made us realize we should have been scientists. Specifically, we should have been the kind of scientists that get this kind of funding. Psychologists at Queen's University Belfast in Northern Ireland asked themselves whether cats were right-pawed or left-pawed, and you've wondered it, too. We certainly have. They wanted to see which paw cats favored, so they gave 42 different cats a jar with a bit of tuna in it. The only way they could get it out was to reach in and, well, fish it out — when they did, they'd show which paw was dominant.

There were 21 males and 21 females in the test, and 20 of the males were left-handed, with one ambidextrous over-achiever. Twenty of the females were right-handed, and one girl, in true cat spirit, refused to conform to any human societal expectations.

Cats develop dementia like humans do

Cats might have nine lives, but they still, sadly, don't live as long as we do. They're living to older ages, though, and those advances in everything from health care to pet food have made us realize something completely heartbreaking. Not only do their brains look like ours, but they act and age like ours do, too. Cognitive dysfunction happens in a lot of older cats, and can typically start to set in around 10 years of age. The condition gets progressively worse, and the symptoms are similar to those seen in humans that have been diagnosed with Alzheimer's or dementia.

Signs vary, and include things like a lack of interest, long and random pauses of staring into space, disorientation, random wanderings, and loud meowing, especially talking when no one's around. As cats age, other problems, like arthritis and blindness, can add to the problems, confusion and disorientation that develops.

While there's not anything we can do to keep away the effects of aging (if only), there are a few things we can do to help. Antioxidants and vitamin E are thought to help at least slow the aging process, and environmental factors can make a big difference, too. Don't bring other animals (or other kinds of chaos) into the house, keep things in the same, familiar places, and make sure you keep accessibility in mind when it comes to things like stairs.

That one was pretty depressing, too, we know. It's absolutely the last sad one, we promise.

Some cats are heat-sensitive color-changers

We feel like we have to make it up to you for all the sadness and oh, have we ever, with just one incredibly awesome fact that'll make you forget all about senile cats forgetting who you are. What about the fact that some cats are heat-sensitive, and can change their color based on their environment? We know, right? You're welcome.

So, how the hey does that work? A helluva cool bit of science, that's how, and here's the short version. There are eight different sets of genes in each cat that governs what color they're going to be. Siamese cats (and their close cousins) have a gene modifier called a Siamese allele. That particular allele blocks color from getting to the cat's fur, which should, in theory, make them albinos. But it doesn't, because it's only activated by heat. Once the temperature gets up to around 100 degrees, the color stops. That's why the cooler parts of a Siamese cat's body (nose, ears, paws) are usually dark, while the rest of their fur stays light. That's also why they're born white. When they're still inside Mom, the temperature's obviously pretty warm and keeps their color gene from activating. It's only when they hit the cool air that they start to color.

We're not done yet. It doesn't just happen once — these cats can change color any time when the temperature of their environment changes. There's also two different forms of the Siamese allele, one that creates the incredibly dark, distinctive markings of a Siamese, and another that's found in Burmese and Tonkinese cats that does the same thing with a lesser effect. And you thought Siamese cats just looked awesome. They're all awesome in the most 1980s, color-change t-shirt way a cat can be.

Cats are picky eaters because of the way their taste buds work

So, you're in the grocery store, looking for something special for that someone special. A nice can of tuna? Salmon? Tuna's always a win … and so is spaghetti sauce. Tuna in spaghetti sauce? Kitty will love it! You get home, open the can, put it nicely on the plate, paying close attention to your presentation … and the cat turns up her nose. (What, just us?)

Cats are picky eaters, and even if you think you've got them figured out, they'll prove you wrong. That's not just out of spite — they're actually picky because of the way their taste buds work. Cats have always been carnivores, and wild, feral cats still rely on a heavily meat-based diet for their survival. Taste buds convey a huge amount of information, including when something's gone bad or been poisoned. And cats have two different receptors in their tongues that taste bitterness, likely developed to help them pick up on bitterness in a way that's completely different from how we taste things.

Scientists still aren't sure just how cats interpret bitterness, but it's likely that they're more sensitive to certain types of compounds. Some experiments found that cats had absolutely no response to saccharin and were only slightly sensitive to aloin, but were incredibly sensitive to a thing called denatonium. Doesn't sound familiar? It's an additive that's put in chemicals that are potentially deadly, and it's designed specifically to keep pets and kids from eating things that they shouldn't. How cats interpret other kinds of flavors is still unclear, but we're still pretty sure they know what's best.

How far do cats travel?

Cats have just a bit of a reputation for being insufferably lazy, and they are. Most of the time. But if you've ever known an outdoor cat, you'll know they also have a tendency to disappear for a good long while whenever they feel like it. So, what gives?

The University of Illinois headed up a two-year research study that fit 42 cats with radio trackers that monitored their every move. That was literal with some, as 23 of them were fitted with trackers that included vibration sensors that gave a glimpse not just into where they were, but what they were doing. The cats were a mix of ferals and free-roaming cats that did, technically, have a home.

The cat with the biggest patch of kingdom was a male feral who wasn't named in the study, but who we'll call Stewie because why not. Stewie's "home territory" covered a whooping 1,351 acres that included everything from city streets and a college campus to fields. As far as researchers could tell, no one made an active effort to feed Stewie, and he was left to his own devices to not just find food, but navigate his way through busy city streets and rural areas with dangers like coyotes. He even seemed to know what stoplights meant, using them to cross streets before bedding down at wherever was convenient for the night. Holy crap, Stewie, we know people who couldn't do that.

Stewie was a special case, but even cats that technically had homes wandered about 4.9 acres over the course of the study. All the cats favored being close to buildings, and surprisingly, the study also found that housecats allowed to roam had a greater impact on local wildlife than ferals, who relied on hunting for survival. The moral of the story? Don't be hating on Stewie.

So why do cats purr?

We're sorry. We said there would be no dark facts anymore, but we lied. This here might be the darkest of them all, and we apologize in advance.

First, the happy. Even the most marginal of cat people know that cats purr when they're happy. They make the noise by some sort of respiratory magic that happens in their diaphragm and larynx, and just how they do it remains one of the best mysteries of modern science. (It's one that we think we need a grant to be able to study in-depth.) It turns out that the idea of purring at happiness might be a bit of a misunderstanding, and they're actually asking us to keep petting them or keep providing a comfortable lap for them to sleep on. It's more like a polite and dignified request.

Now, the not-so-happy. Cats also purr when they're injured or scared, and researchers think that it has something to do with the healing power of the purr. You absolutely read that right. Cats purr at a frequency of 26 hertz (for most domestic cats), and that just happens to be the same frequency that's been found to promote healing in bone and other body tissues. Crazy, right? But that's the deal, and when cats are injured, they're likely trying to help themselves heal or comfort themselves by the reverberation of their own purr. It's why cats will often curl up with an injured cat (or non-cat) and purr. They're trying to help.

And now, the even worse part. Since cats purr to comfort themselves, it's also something that dying cats have been observed doing. They do it to console themselves and maybe, just maybe, to console you a little bit. Go on, wipe away that tear. That's what we need to do.