The real reason dogs tilt their heads and other canine facts

The bonds we have with our canine companions are unlike any other friendships or relationships we have. Some of us love our dogs like children, and it's no wonder. There's an unconditional friendship there that makes everything better, and knowing what's going on inside those precious, perfect little heads can only make us understand them better.

Why do dogs always act hungry?

Even if you just fed them five minutes ago, your dog will probably give you those eyes when you're trying to eat your lunch. If their behavior is to be believed, they're one stagger away from collapsing from sheer starvation.

So what's the deal, Pup? It's normal, and it's thought that this behavior is a holdover from when we first started inviting wild dogs to share our campfires and our table scraps. No one knew when the next meal was coming. It was better to chow down on food when it was there, and it's likely that the focus on food is biologically hardwired into our dogs today.

For some dogs, there's always the possibility that they've experienced a life of real starvation. Even after being rescued and re-homed, they can remember what an empty belly is like. Vets will often differentiate between begging dogs that act hungry and dogs whose behavior suddenly changes to become more demanding of food, so it's also important to keep an eye on puppy in case he goes from begging to ravenous.

Why do some dogs eat poop?

Horse poop, sheep poop, unidentified poop, sometimes their own poop. It's not like you don't feed them, and it can't possibly taste good … can it?

Poop-eating has a name: coprophagia. There are plenty of reasons a dog might be doing it, and sometimes it's a problem. Other times it's just a disgusting, annoying habit, made even more disgusting if you get licked afterward. Most puppies sample poop at some point because puppies are dumb. (Most, thankfully, grow out of it.) Nursing mothers will often eat the poop of their puppies to clean up after them, and some puppies will see Mom doing it and think it's what they should be doing, too. Puppy see, puppy do.

Some poops (like cat poops) are just interesting snacks. In some cases, it might be a sign of a behavioral issue brewing. Do they spend too much time alone? Are they doing it just to get your attention? It's entirely possible.

There are some medical causes for the behavior. If adult dogs suddenly start wolfing down poopsicles, there might be a problem. If they aren't getting enough nutrients, they might be trying to supplement their diet. That can happen if they're on low-quality food or if they're developing some underlying condition like diabetes. Dogs are smart, but dogs can also be kinda gross.

How many words do they understand?

The short answer is, "More than you think." The long answer is a bit complicated because researchers have found that it depends on a lot of things, from training and an individual's intelligence to breed, occupation, and how they're spoken to.

Right now, the record-holder for the most known words is Chaser, a border collie from South Carolina, who knows 1,022 words. Chaser has shown the ability to join verbs and nouns together to perform particular tasks, and she can even use the process of elimination to select toys that she hadn't been taught the name of.

Chaser's an extraordinary case, but what about your precious pooch? Most dogs have a vocabulary roughly equaling that of a 2-year-old, with "average" dogs understanding about 165 different words and phrases. The super-bright class (mostly working and herding dogs) understood around 250 different words. That's not entirely surprising, given that we count on these dogs to understand what we're telling them to carry out specific jobs. While research shows our herding friends come out on top, dogs like terriers and hounds recognize considerably fewer words. That might have something to do with their original purpose. While terriers and hounds needed to simply chase, herding dogs needed to be able to follow commands and make snap decisions on their own, which has translated to smarter dogs today.

How efficient are they at learning new things?

An awesome experiment from Yale University's Canine Cognition Center found that most dogs are not only incredibly good at learning new tasks, but they're very good at figuring out how to cut out extra steps and make whatever they're doing more efficient. How good? Better than a human toddler.

Researchers gave some toddlers a puzzle box and showed them how to solve it. The process involved pulling a lever that did absolutely nothing, and the kids couldn't get their heads around how they didn't actually have to pull the lever to open the box and get their treat. Even if a task step is useless, they still do it. It's called overimitation.

Dogs, on the other hand, were able to figure out which steps they could drop and still get to their end goal faster and more efficiently. Even though they went through the useless steps at first, dogs were able to adjust what they had learned on their own. That essentially means that they listened to the advice they were given, then took it upon themselves to filter out the stupid stuff. Who's a good boy?!

Why do dogs roll in the worst-smelling stuff on the planet?

Any dog owner will recognize the shoulder lean, the butt in the air — Pupper's just found something fun to roll in. It's making your eyes water already, so how can dogs, with their superior sense of smell, even stand it?

Dog behaviorist Stanley Coren, a canine behavioral psychologist, took a crack at figuring out why they can't seem to stop themselves. He noted that the things dogs choose to roll in are usually organic things, whether it's the remains of a dead animal or poop. After going through a bunch of theories that made no real sense, he came to a couple different conclusions. One is the idea that it's an evolutionary throwback to the days when they were living in packs and hunting. Rolling in something stinky likely served to mask their own scent and might allow hunting packs of dogs to get closer to prey before being detected.

His other idea? For most humans, sight is the primary way of receiving sensory information about our surroundings. When we see something particularly powerful, we're moved by it. It's the same thing for dogs, only their sense of smell is their most powerful input. The stronger the smell, the happier they are. So basically, your worst fears are true: Pupper really might be rolling in dead things just because he likes being stinky.

What's with the butt-sniffing?

As a mere human, you're probably baffled by what could possibly be so interesting about the smell of dog butt. Factor in the idea that some dogs have a sense of smell that's up to 100,000 times stronger than ours, and seriously, what's with the butt-sniffing?

Butt-sniffing dogs are getting a whiff of each others' anal sacs. Chemical secretions from the sacs contain lots of information (right down to diet and current emotional state), as poorly designed as the whole thing might seem.

Right, so what about the elephant-farts in the room? Wouldn't other backside smells override any sort of chemical a dog's giving off? The chemical compounds are only half the communication network; dogs have a super-sensitive receptor in their noses called the Jacobson's organ. This receptor is tuned to the particular acids secreted by the anal glands and tunes out poop and fart smells. That's the same organ used when dogs sniff around the popular pee tree at the dog park.

Does that make you feel a little better? You dog doesn't have a weird fetish after all, just an odd way of shaking hands. And before you get all judgmental about Pupper's funk, don't forget that humans have the same sort of glands that dogs do. Ours are mostly in our armpits and groin, which is why some dogs are dedicated crotch-sniffers.

What's with the circling?

Stanley Coren, PhD, decided to get to the bottom of this one. He tested 62 dogs on various surfaces to see what kind of behavior they demonstrated before lying down. He found that dogs who were put into an area with an uneven surface (shag carpeting) were three times as likely to spin in at least one circle before they settled down.

Coren believes that confirms at least part of one theory: they're simply trying to get comfortable. Other parts of the theory suggest that this behavior is also hardwired into them from their wild days and that the circling is partially scaring away any bugs that might bite, kicking away any sharp rocks or sticks, and simply just making the ground more suitable for snoozing.

Do dogs get jealous?

Ever come home from visiting a friend and their dog and get the feeling that you're being eyeballed for the traitor you are? You absolutely are.

Stanley Coren took a look at this one too, and he found some of his first proof in the relationship between a mother dog and her puppies. Let's face it — puppies are adorable, and the clueless little poop-machines are the ones getting all the attention. He observed mother dogs shoving their puppies away in an attempt to get human affection, as though Mom was getting jealous of all the loves her own pups were getting.

There have been a handful of experiments done to see how dogs react to unfair situations. In one, two dogs are tasked with doing the same thing, but only one was rewarded. Anyone who has dogs can predict how that one went. Another experiment put dogs in a position where their owner's affection was intercepted by a stuffed dog, and again, you can pretty much guess how that played out. Dogs weren't usually bothered when their owners paid more attention to something like a book, but when it was another pseudo-dog? Oh, hell no.

Weirdly, this is another time that dogs show distinctly childlike behavior, as the results of the dogs' test were similar to the results of experiments done with toddlers who watched their parents play with life-like dolls instead of them. So when we call them fur-babies, we're not too far off.

Do dogs dream?

As much as we want to, we can't get Rover to tell us what's going on when he starts running in his sleep or making those adorable little *boof* sounds. However, educated guesses suggest that they're dreaming just like we do. Letting sleeping dogs lie and then monitoring their brain activity reveals patterns similar to sleeping humans. Like us, they also have a part of the brain called the pons, which keeps us from acting out our dreams (most of the time). It seems to function the same in dogs — puppies and older dogs seem to dream the most because the pons isn't as active in those dogs as it is in adult dogs.

Dogs enter REM sleep about 20 minutes into their sleep cycle, and even if they aren't running in their sleep, you should still be able to see signs that there's something going on in there. From eye twitches to ear twitches and those little barks, they're dreaming. What's more, it's thought that dogs are dreaming about what's most important to them. A dog that spends his day hiking is likely dreaming about wandering through the woods, while one that lounges in the kitchen all day is probably dreaming about dinner. One Harvard psychologist suggests that closely bonded dogs are likely dreaming about their favorite person. Seriously, can they be any more perfect?

Right-pawed or left-pawed?

Just like humans, dogs can be either right-handed or left-handed. Unlike humans, there's an equal chance of your dog being either right- or left-paw dominant, or ambidextrous. There are a few different ways you can test to see which your pup is, and it just involves paying attention to which paw is used to do things like give high-fives and steady toys.

Humans have always had a sort of bias against the left-handed — weirdly, researchers have found that the bias might be alive and well in dogs too. They found that left-pawed dogs tend to be more wary, or even aggressive, toward strangers, and even though it's a relatively slight correlation, most guide and service dogs are right-pawed or ambidextrous, as many left-pawed dogs are weeded out because of temperament.

There also seems to be a connection between how dominant your pup's paw preference is and how brave they are. Pups that are ambidextrous tended to be more anxious, while dogs with a strong preference to a dominant paw were quicker to adjust to new situations and were less easily rattled.

What's with the tail?

It's so easy to get sucked into everything else about a dog, you might overlook what's going on with your dog's tail. It wags when they're happy to see us (i.e., always), it wags at dinnertime, and it's up during playtime, but researchers have found that a left-wag and a right-wag can mean entirely different things. When Pupper sees the person that she's closest to, that usually gets a tail wag to the right. That's when the tail is the highest, too, and careful studies show that dogs tend to wag their tails to the right when they see new people, although the tail was generally lower. Even cats got the same right-side wag, but unfamiliar, pushy dogs? *left-wag, left-wag, left-wag*

What's the deal? Right wags mean that it's the left side of the brain that's working hardest, and that's the side that processes positive experiences, happiness, and excitement. When your dog sees you and her tail starts going, it's a physical display of happy. But when she's nose-to-nose with an unfamiliar dog that might or might not be friendly, the left-side wag is coming from the right side of the brain. That's where things like caution and fear come from, and that's also where dogs process new experiences and objects.

The height of a tail wag also means different things. A relaxed tail is a relaxed dog, while a low tail is a submissive or ashamed cue, and a high tail can be a sign of dominance or excitement. When their hips get involved with a wag, that's a real sign of happy.

What are the rules of dog play-time?

If you've ever spent any time coexisting with two or more dogs, you've probably seen them play together. Things can go sideways in the same way they do with human siblings, and there are a lot of myths about what dogs are doing when they play.

You've probably heard that the dog showing its belly is being the submissive one. Not true, at least not when it's playtime. Studies have found that playtime behaviors are governed by a different set of rules than non-playtime behaviors, and that's one reason dogs have so many tells that say, "See, I'm just playin'! This is fun, right?!" Rolling over during play was found to most often be a sort of countermeasure, used to avoid a headlock or bite hold by the other dog, and it was never linked with any other kind of submission. The position allows the roller to deliver some play-kicks, and it was also found to be a strange sort of opposite to submission.

The study found that in pairs of play-fighting dogs, it was the larger, more dominant dog who would roll on their back. That, experts say, is likely their way of leveling the playing field, to let a smaller or weaker dog get in some licks and bites. It's called self-handicapping, and it's a way for a stronger dog to encourage a smaller one to play.

Why do dogs chase their tails?

Perhaps nothing amuses humans more than when a dog chases her tail. It's a hilarious behavior, and it's even funnier if she manages to catch it. But what's going on here?

A few things that might be happening, and all dogs are different. Some dogs might simply be doing it because they're bored at that moment, and it seems like a fun way to fill the time. For some that do it regularly, it might be a sign of a condition called canine CD — OCD for dogs. These dogs might show other kinds of compulsive behaviors, too, from licking to random barking. Here, it might be a problem but, for other dogs, it can be completely harmless. Some breeds are more likely to do it than others, probably one of the weirdest breed-specific characteristics.

Oddly, there might be a physical component to it — dogs with high cholesterol tend to chase their tails more often. Basically, they have mood changes that go along with their cholesterol levels, which likely has something to do with the overwhelming urge to catch that durned tail.

Or they might be doing it to get your attention. Do you scold them when they do it? Do you laugh at them? Positive or negative, it could just be for you. In most cases, it's a harmless behavior. If it does become a problem, though, it might require therapy to correct. Hey, at least at the therapist's office Puppers is encouraged to lie on the couch.

What does the world look like through a dog's eyes?

The idea that dogs can only see the world in black, white, and gray is a long-standing myth. Studies done at the University of California found that dogs can more accurately be described as seeing the world in shades of blues, grays, yellows, and browns. What they can't see is, weirdly, some of the most popular colors for dog toys on the market today. Things like bright orange and bright red? Those are just nice for us humans.

If they can see shades of colors, how do they process that information? We aren't entirely sure, but it seems they can learn to do just that. One study linked different boxes with different rewards. Most dogs seemed to associate a light yellow color with a better reward.

There are a few other fascinating facts about canine vision that might change the way you see your dog's world. Compared to us, dogs are also nearsighted. They tend to be around 20/75, which means things are fuzzy in the distance (which might explain your dog's reaction to things down the street). They have a huge advantage over us in the dark, though, as their eyes contain a lens called the tapetum lucidim. It reflects what light is available (and makes their eyes glow in photos), and while they're not as good in the dark as cats, they're much better than we are. They have a much wider field of vision than we do, too. While we can see about 190 degrees around us, Fido can see about 250 degrees.

How do they make us love them?

The bond between a human and their best dog friend is a special one. Put the time and effort into building up a relationship with your dog, and you'll be rewarded exponentially with a friend who's always there for you, always ready to listen, and always ready to do whatever it takes to get a smile. Listen to some people describe their dogs and it's clear that they're every bit as close to them as they would be to a human child. As it turns out, that closeness has a biological basis.

Studies have shown that when closely bonded dogs and humans make eye contact, it releases a chemical called oxytocin in both parties. That's the stuff in the brains of mothers and their biological children that's credited with a feel-good sensation that strengthens emotional bonds. The same thing happens when we build a relationship with our dogs, and it's a weirdly specific, special sort of reaction. Researchers have also tried the same experiments with wolves (even those raised by humans from pup-hood) but didn't get the same chemical connection.

Other studies looked at just what goes on in human brains when dog owners were shown pictures of their super-special-best-dog-ever. The study showed similar patterns to what happened when mothers were shown pictures of their children, and they also suggest that dogs know full well what they're doing. Over the last few millennia, once we started keeping dogs as pets and companions, it's thought they adopted more and more childlike behaviors in an attempt to cement their role in a parent-child relationship. And usually, it works.

How close are you and your dog?

Dogs are man's best friend, and there's a good reason for that. They're perfect. They give us unconditional love, and they don't care how bad a day we've had, they just want to make it better. And they do, but you might not even realize just how in-tune to us they are.

Neuroscientists from Atlanta's Emory University looked at just how connected we are to our favorite dogs. (No matter how many you own, you know you have a favorite.) They looked at what a dog valued more: a food reward, or praise from their Special Person. Dogs were trained to associate a pink truck toy with food, and a blue knight toy with praise and loves. After they had the associations down, they started monitoring brain activity to see how happy they were with praise or food. Of the 13 dogs in the study, four were happier with love and attention from their people, while nine were equally happy no matter what they got. Only two made food their priority. They also set up a test where dogs could choose to go to their owners or a bowl of food: the overwhelming majority chose their owners.

Not sure where your dogs falls? Try yawning in front of him, and see what he does. We might not be sure why we yawn, but we do know that it's contagious. It's catching for dogs, too, and a study from Duke University's Dognition website found that dogs who share an incredibly close bond with their owners tend to share their emotions. That's most obvious with yawning, and if you and your dog share a close emotional bond, you're more likely to catch a yawn from each other.

However, dogs who score high in cunning, emotional manipulation, and attention-seeking behaviors are also more likely to yawn. We'll leave it up to you to know which one your precious pupper is.

Why do dogs tilt their heads?

Besides how it's absolutely adorable (like everything else about dogs), we know little about why dogs tilt their heads, though we can't help but melt a bit when they do it. Though if you ask some people, that's exactly why they do it.

Part of our connection with dogs is because their emotional intelligence is off the charts. Perhaps they tilt their heads because they're reading our emotions and looking for the positive response they usually get when they do it. (That's right, your dog is trying to make you smile. It might be in hopes of getting out of trouble, but kudos for ingenuity.)

There are a couple other theories, too. Depending on the shape of your dog's head, they may be able to improve their ability to pinpoint the location of a noise if they adjust the position of their ears, clearing their line of sight at the same time. Studies have shown that dogs with longer muzzles tend to do this more, so it's likely there's some kind of physical or sensory benefit they're getting from it. Hold your fist in front of your face to mimic a dog's nose, then move your head to see what sort of difference it makes in your line of sight. Go ahead, we'll wait.

Yet another theory suggests they're just concentrating particularly hard, trying to read what you're communicating and seeing what words they recognize. They're looking and listening for social cues to figure how they're going to react, and waiting to see if you're going to say something good or something bad. Experiments on dogs' interpretation of language found they'd tilt their heads right when they were spoken to with emotionless words and left when the words were full of emotion, both good and bad. That seemed to suggest it has something to do with the way they process information, and it might mean they have separate processing centers for emotion and words.

They're such good, smart baby-dogs. So good.