1. The muzzle grasp

When two dogs are hanging out and then one appears to bite the other’s muzzle, it can be a bit shocking to the owners, but it isn’t something to be worried about. This is just a social behavior dogs got from their wolf ancestors. The dogs are affirming their social relation: the dog being grasped is insecure and making sure it’s still the other dog’s pup.

Puppy muzzle grasp fight
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Muzzle grasping is usually done between dogs who know each other well, but insecure dogs can also ask a human can do it. If your pup approaches you while puffing its nose, you can gently grasp its muzzle and reassure it that you’ll take care of it. He’ll be happy to know it.

2. Cat in the box

It’s no secret that cats love cardboard boxes. From small indoor cats to big tigers, they can’t get enough of the box. They like to sit in boxes even if they barely fit. It seems that, for domestic cats at least, boxes reduce their stress by providing a safe enclosed space.

Cat in box
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Cats like a place where they can observe others, but not be seen. They like to hide from predators and prey, which boxes help with. Or at least cats feel like they do. They might also like boxes for their warmth or maybe they just want to explore the new thing in their environment. We still don’t really know.

3. The head tilt

You might have noticed that sometimes when you talk to your dog, she tilts her head to the side. It’s very cute, but why is she doing it? Well not much research has been done on this, so scientists don’t have a clear answer but they do have some plausible hypotheses.

Dog head tilt
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There are two possible reasons for the head tilt. Dogs might be tilting their heads to get a better view of your facial expression, because it could be hard to see around a long muzzle. But they might be doing it instead to hear you better, possibly by adjusting their floppy ears.

4. Flehmen response

If you’ve ever seen a cat with a particularly funny look on their face, they may be doing something called “flehemen.” Look for an open mouth with drawn back lips; maybe the cat looks kind of disgusted or grimacing. Don’t take offense, because there’s a different reason for this expression.

Flehmen cat response scent
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The flehemen response is actually a kind of smelling method. Instead of sniffing with their nose, the cat is drawing air over an organ on the roof of their mouth. This organ is called the vomeronasal organ and it can smell different scents than the nose. Other animals, like tigers and horses, do this too.

5. Yawning

While a person yawning is perceived as bored or tired, yawning actually has a different meaning to dogs. Your dog’s yawns aren’t necessarily a sign of tiredness, but are often a pacifying behavior. They’re doing it to show friendship and peace to you or another dog. And they probably interpret your yawn the same way.

Dog yawning
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While yawning may have served a more physiological purpose originally, it’s evolved to become a form of communication. As with many dog behaviors, it evolved as a part of their social pack behavior. Hierarchy and dominance is very important in a pack, so communication is important. If you yawn back, you’re affirming the peace.

6. Licking your face

Some find it endearing, others find it annoying, and many find it gross, but dogs keep licking people’s faces. Even some wolves do it to humans.  Why are they doing this? Well, it’s to show they think of you as a friend and to suppress any aggressive or dominance behavior.

Dog licking face
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Licking your face is a dog’s gesture of peace, so the best response to it is to close your eyes, turn your head away, and yawn. To the dog, this means you accepted their friendship. On the bright side, the germs from their tongue are no worse than the germs you get from kissing other humans.

7. For the love of catnip

Cats are notorious for going crazy for catnip. They rub their bodies all over it and some even lick it up. This behavior is actually a response to a chemical compound, called nepetalactone, that the catnip is producing. For the plants, nepetalactone wards off insects, but for cats it does something quite different.

Cat with catnip
Image by Michele Pevide/iStock

Scientists think nepetalactone is similar to cat pheromones, which are chemicals animals use to communicate. The nepetalactone molecule goes into a cat’s nose and then binds to the same receptor a pheromone would bind to, this effectively signals to the cat’s brain that there’s tons of pheromones around.

8. Catnip on the brain

Researchers investigated what catnip is doing to cat brains and found that catnip, through the molecule nepetalactone, is stimulating three areas of the cat brain. It affects the olfactory bulb, which processes smells, the amygdala, which is tied to emotions and decisions, and the hypothalamus, which is involved with a number of things, including sexual response.

Cat catnip
Image by Sydney Baum-Haines

The hypothalamus stimulation may be the reason for the rolling around, which is what female cats do when in heat. It may also be why kittens don’t normally react to catnip until they become sexually mature. But not all adult cats go wild around catnip, because the reaction is genetic. However, catnip craziness isn’t limited to pet cats, some big cats love catnip too.

9. Panting for a cause

You’re probably used to your pupper panting with his mouth open and tongue lolling out, but do you know why he’s doing that? Dogs pant to cool down because the evaporation of their saliva removes heat. Humans sweat to do this, but dogs only have sweat glands on their paws so they can’t get rid of a lot of heat that way.

Dog panting behavior
Image by Akchamczuk/iStock

When breathing hard and fast, dogs evaporate more water. Letting the tongue hang out also increases the amount of evaporating saliva and cools down the blood circulating in the tongue. All mammals pant under certain conditions, like when it’s really hot or from overexertion. Just make sure to give your dog some water when he pants, because he’s losing a lot of water from doing so.

10. Just shake it off

Have you ever been caught in an unwanted shower when your wet dog voraciously shakes itself? Well that behavior evolved for a very important reason: keeping the doggy toasty warm. Fur needs to be dry to keep an animal warm, because it can’t trap air when it’s wet.

Dog shaking off water
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Since an animal could get hypothermia when wet in cold weather, getting dry quick is crucial. Other mammal species, like mice and bears, shake themselves to get dry too. Animals have to shake hard enough to break the water’s surface tension, so smaller animals actually have to shake faster. Dogs get help from their loose skin flapping around, because it helps to throw off water.

11. Scratching everything

While cats are adorable, they can get annoying at times. One of the worst things cats do is scratch the furniture, carpet, and just about anything. Unfortunately, this is a natural behavior for them. Scratching is good for their claws, because it removes the dead outer layer of the nail.

Cat scratching chair
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Plus, scratching stuff serves as a way for cats to mark their territory. Cats are pretty territorial, and are used to living alone, so they don’t like other cats encroaching on their area. Cat paws have scent glands, so the smell and visible scratches serve to warn other cats, “This is my territory!”

12. Not the couch!

Not only is scratching good for their nails and for marking their territory, it also helps cats stretch their back and shoulder muscles. So maybe your cat is avoiding your small scratching post because it can’t get a good enough stretch on it. Don’t you just love a good stretch?

Cat scratching post
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And if your cat didn’t have enough reasons to scratch your furniture, it seems that scratching is also a stress reliever and emotional release. Your cat may do it when she’s anxious or excited or frustrated. Whatever the reason your cat is scratching, to get her off the furniture and carpet, you should give her a tall scratching post.

13. Rolling in the grass

When dogs go to the beloved outside, they like to roll themselves all over the grass. Why do they insist on doing this? It might be another leftover behavior from their wolf ancestry. Wolves will roll around in an interesting odor to get it on their body and then bring the scent back to their pack.

Dog rolling in grass
Image by Kevin Ekmark/Flickr

The pack then sniffs the scent and may even follow it back to its origin. Maybe your dog is finding an interesting smell and bringing it to you, because you’re its family. Or maybe it’s rolling in the grass for an entirely different reason. There’s a few other possible explanations.

14. Stinky and itchy

While your dog may be rolling around to bring you a cool new scent, he might also be doing it to get rid of an unwanted smell. Perhaps you bathed him with something that smells too strong, and he just wants it off. Next time, bathe him with something that has no scent and he might be happier.

Dog getting bath
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But if your dog is especially itchy, he may just be trying to get a good scratch in. If he’s seems especially itchy, he might have some kind of bugs bothering him and you should probably have him checked out. Since there’s a few possibilities for rolling in the grass, pay attention to your dog to figure it out.

15. Pupper’s appetite for grass

When they’re not rolling in it, they’re eating it. Why do dogs like to eat grass? Well if they’re not feeling well they might eat a bunch to make themselves vomit, but this doesn’t happen every time. So why else could they be eating it? It probably goes back to their pre-modern life.

Dog eating grass
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Since dogs were scavengers and had to eat whatever they could find, they’re pretty much down to eat anything nowadays. And since anything includes grass, they eat grass. It might be providing a good source of fiber and minerals for your pup. Cats, however, eat grass for a different reason.

16. Kitty’s appetite for grass

When you let your cat outside, they take in some sun and then start munching on the grass. And then they probably throw up the grass they literally just ate. Cats can’t digest plants (although they might get a vitamin from it) so why did they bother eating it in the first place?

Cat eating grass
Image by Salima Senyavskaya/Getty Images

It’s likely that cats eat grass to throw up other indigestible material in their digestive tract: the bones, fur, and feathers of their prey. Your cat might not eat live animals now, but it’s pretty hard to get rid of a behavior that natural selection has been working on for millions of years.

17. The mysterious purr

Few things bring more joy to a cat person than their kitty purring; it’s soothing and comforting. But while cats often purr when cuddling, they also do it in dramatically different situations, like when they’re in pain or giving birth. Since it’s done in such different emotional circumstances, it isn’t considered communication.

Cat cuddling purring cute
Image by Denis Valakhanovich/iStock

In fact, scientists think it’s actually a form of self medication. Low frequencies have been shown to help build bone density, and cat purrs fall right in this range. So purrhaps, cats are purring to heal and maintain healthy bones. And it’s even possible that your bones could benefit from being next to their pawsitive vibrations.

18. The unwanted present

It’s not fun coming home to a wounded bird or rodent in your home, but your cat doesn’t understand your revulsion. She’s gone out and caught this animal just for you. When wild cat mothers raise their kittens, they start teaching them how to hunt by bringing back prey.

Cat hunting
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This present starts the kitten eating meat instead of milk, but also provides them with something to test their hunting skills on. So when your cat brings you an unwanted present, she’s probably trying to teach you how to hunt. But since male cats can also bring back these little gifts, it may be the cat’s instinct to get its prey to a safer place than where they caught it.

19. Following into the bathroom

Dogs just can’t seem to give you any privacy. They tend to follow their owners into the bathroom, which can be a little uncomfortable, to say the least. Sure, it’s nice to have a bathroom buddy when you’re out in the woods at night, but in your own home, it’s really unnecessary. Despite that, dogs have their pack mentality and they just don’t see privacy the way you do.

Dog in bathroom behavior why
Image by Chris Amaral/Getty Images

Dogs’ wolf ancestry is most likely to blame. Since you are part of your dog’s pack, he’s just showing his loyalty. Or perhaps he’s just very curious about what you do when you close the door. However, if he consistently follows you everywhere it may be because he’s insecure or thinks you need to be guarded all the time. These behaviors can become dangerous and consulting a veterinarian could be the best option.

20. A good ol’ tail wag

Dogs are well known for two things: being man’s best friend and wagging their tails. Generally, a dog’s tail wag is accepted to mean happiness and friendliness, but it may actually be more nuanced than that. For instance, if your dog is wagging its tail slowly, that means he’s feeling uncertain.

Dog wagging tail behavior
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However, if he’s wagging his tail energetically it means something else entirely. Most likely it means the dog is happy and excited, but a couple of studies have shown that the side he wags on can mean different things. Who knew a dog’s tail wag could communicate so much?

21. Wagging right vs. left

Your dog may be telling you more than you think with how she wags her tail. If your pupper wags slightly more to her right side, it means she sees something she wants to approach. Most likely this is a human, like you. However, if she wags more to her left side, she might be looking at something she wants to avoid.

Dog wagging tail
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Your dog might want to avoid a more dominant dog. When scientists showed videos of dogs wagging their tails to other dogs, the watching dogs were anxious about left side wags but pretty calm about right side wags. But if your dog wags her tail right in the middle, who knows what it means.

22. It’s all in the tail

The further we get into the tail wagging business, the more complicated it gets. For instance, if the tail is wagging widely, it’s probably a more positive sign than a tail wagging in tiny movements. But of course, dogs do use their tails to communicate in other ways than just wagging.

Why dog wags tail
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If your dog has his tail lowered between his legs, he’s probably scared, anxious, or submissive. But if your dog has his tail held high, he might have seen something really interesting, or it might be a threatening and dominant signal. A middle tail height probably means your dog is relaxed and happy.

23. Kitty’s raised tail

While dog’s tails are often wagging, cat tails aren’t as energetically expressive. However, it can still tell you something. When a cat walks up to you with its tail held high, it’s greeting you. Give that kitty a little head rub and it may in turn rub up against you.

Cat raised tail behavior
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The rubbing or head butting is probably your cat’s way of marking you with its scent, although if it’s a strange cat that you’ve just met, she’s probably trying to get information about you. While this is behavior cats do to other cats, there’s one common behavior that cats only do around humans.

24. Meow

You learn it as a child, dog goes bark and cat goes meow, but they don’t exactly teach you what those meows mean. If you’ve ever owned a cat, you likely know that meows mean different things in different situations. Plus, it varies between individual cats. But you might not have known that cats only meow to humans.

Cat meowing why
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While kittens meow to mom, when hungry, scared, or cold, adult cats don’t meow to each other. They communicate with each other in other ways, like hissing, growling, and scent marking. So when your kitty is meowing, they’re trying to tell you something, like feed me, pet me, or maybe just hi. Pay attention to your cat and you’ll probably learn to distinguish the different meows.

25. The exposed belly and attack

Cats are well known for exposing their belly and then attacking if you try and rub it. Of course, there’s the rare cat that actually lets you rub their belly, but most don’t like it. When cats do show you their tummy, they’re really showing that they trust you.

Cat fluffy belly rolling over tummy
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Then you break their trust when you reach for it. A cat’s belly is its most vulnerable body part because right under that fluff are their crucial organs. So instead of going for the belly rub, pet your cat’s head instead. Of course, a few cats actually like their belly rubbed, but you have to risk the scratches to figure out which ones.

26. Burying the toy hatchet

You might be getting annoyed at your pup for digging in your garden and burying things like toys and food, but your dog isn’t just going to lose an instinctual behavior so quickly. Out in the wild, food is a precious resource compared the plentiful bounty of the food bowl.

Dog digging in ground
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Dogs’ ancestors buried food so they could come back and eat it later. Maybe they found too much food for one meal, so they had to take a doggy bag back to the hole. Just think of your garden as your dog’s very own refrigerator and not, well, your garden.

27. Regurgitation near puppies

You’ve heard of mama birding, but what about mama dogging? Mama dogs sometimes puke up their food near their puppies. She isn’t sick, she’s actually feeding them. Of course these puppies could just wander over to their food bowl and eat there, but it’s a trait from a time when they couldn’t.

Dog with puppies
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In the wild, wolf cubs can’t hunt for their own food, so the parents’ help is needed to feed them. It might be kinda gross to you, but mama dog is just trying to do her mama-birding best for her puppies. So, don’t get too mad at her when she vomits for her puppies.

28. Making biscuits

One strange thing cats do, as cat people lovingly call it, is make biscuits. They knead their little paws on blankets, furniture, and you. It’s pretty cute, if painful, but why do they do it? Most scientists think it’s a neotenic behavior, meaning it was a juvenile behavior that adults just kept doing.

Cat kneading behavior
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Kittens knead their mothers’ bellies to make her make milk, and since some adult cats also suckle when they knead, this explanation makes sense. However, adult wild cats don’t knead, so why do domestic ones? While cats are fairly similar to their wild counterparts, domestication has changed them in a few ways.

29. Do they need to knead?

Kittens knead because it’s necessary for getting milk, but wild adult cats don’t. Yet domestic adult cats do, so what gives? It turns out that neotenic behaviors, like kneading, are mostly found in domestic animals and not in their wild cat relatives. So while cats aren’t super different from domestication, this seems to be one change.

Cat happy kneading behavior
Image by Celeste Lindell/Flickr

The neotenic behavior is likely because humans artificially selected sociable and less aggressive cats, which are traits more similar to kittens than full grown wild cats. Generally, wild cats are loners, but house cats aren’t nearly as much. So kneading has become a way for adult cats to show they trust you and feel safe.

30. Circling before bed

As the day (or the article) winds down, it gets to be time for bed. Your dog wants to join you, but first she circles around a spot a few times before settling in. Why? Well, back when dogs lived in the wild they had to make the ground suitable for sleeping somehow.

Dog sleeping bed
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Grass and dirt certainly aren’t as comfortable as a plush bed, but dogs made it work. If the dog was settling down in a grassy area, she probably needed to pat down the tall grasses, so circling was a good way to do that. Plus, the movement might have driven out insects and reptiles that could threaten her puppies.

31. Sleepy kitty

Have you ever thought, if only I was a cat and I could sleep all day? Well maybe all that fantasizing stopped you from wondering why they sleep so much in the first place. People think it all comes back to their past eight lives as hunters.

Cat sleeping window sill
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Hunting takes energy, so sleeping a lot conserves that needed energy. Also, cats’ prey often come out at dawn and dusk, so that’s when cats are the most active. For much of their 12 or so hours, cats are just dozing in a light sleep so they can quickly get up if needed, but they do take short deep sleeps, too.

32. Why do cats lick you?

It’s super cute when your cat licks you, as it feels like they really do care about you. But then, after a few licks, it feels like someone’s rubbing sandpaper on your skin. Their tongues are made for ripping meat off the bone, so why are they licking you? Well there’s the other thing their tongue is for: cleaning.

Cat licking person
Image by 1001slide/Getty Images

Cats are great because you don’t need to bathe them, and that’s all thanks to their barbed tongue. Sometimes, cats will groom other cats, usually members of their family. So your cat might be grooming you, seeing as you’re part of her family. But there are some other possible reasons your cat likes to lick you…

33. Rough sandpaper kisses

Cats might lick (or even bite) you for attention. They want something, maybe play or pets. But if it’s excessive licking, the cat might be stressed about something. However, sometimes your cat licks you just because you taste interesting. Maybe you spilled something on yourself or you’ve got water on you from the shower or your cat just likes the salt on your skin.

Cat licking person behavior
Image by Tycson1/iStock

But there’s also the fact that your cat may just be licking you to show affection. Cats do this to each other, so they might be just showing you some love and wanting some love in return. Licking often means the cat is calm, but since there’s several possible explanations, pay attention to the context of your cat’s licking to figure out the real reason.

34. Rolling over while playing

While rolling over can often be submissive behavior to stop aggression, during play it means something entirely different. Researchers watched a lot of dogs play, analyzing their behavior when they rolled over, and found that the dogs weren’t being submissive at all.

Dogs playing together
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The dogs rolling over are just playing, and want to keep playing. Often, they do it to avoid a play bite, but sometimes they do it to get into a better position to give a play bite. Either way, the dog rolling over is not saying, “you went too far and I want to stop.” In fact, some people think bigger dogs will roll over to give the smaller dog a fairer play fight.

35. Barking their heads off

Wolves don’t bark much at all, compared to the other sounds they make. But domesticated foxes bark, when wild ones don’t. So what’s the deal with barking and why do dogs do it? Because sometimes they bark so much you just want to go back to the shelter and trade your dog in for a new one.

Dogs barking
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Well, their barks have different meanings. When they bark at a stranger, it sounds different than when they’re just barking alone or when they’re playing. But it seems like it has something to do with their domestication and the fact that they were bred to be less aggressive. Unlike the cat’s meow, though, dogs do seem to communicate with each other by barking.

36. Your dog is just so excited to see you again!

There’s nothing better than coming home to your dog. He’s overwhelmingly excited and acting like it’s been days, even if it’s only been a few hours, since he last saw you. Why do they do this every time you come home? Scientists took a peek into dog brain scans to understand it better. The smell of familiar humans triggered their brain’s reward center like no other smell did.

Happy dog home person behavior
Image by yacobchuk/iStock

Plus, scientists did an experiment and found that the reunion of owner and dog is quite similar to a reunion between a human mother and child after they’ve been apart for some time. Dogs are very social and don’t like to be left alone, so they get real excited when you finally come back.

37. The ease of litter box training

While dogs need tons of training to get them to even do their business outside, cats can easily be trained to use a litter box. In fact, whenever you get a cat or kitten, they’re usually already litter box trained. And it isn’t easy to train them to do anything else, so why is this training so easy?

Image by AlbinaTiplyashina/iStock

Well, it turns out that cats usually hide their excrement to hide the smell from predators and other cats. Soft dirt, sand, or litter are just very easy materials to cover their fecal “treasures” with. However, sometimes dominant cats in a group won’t cover their feces, as a way to mark their territory.

38. Your kitty, the climber

Cats love to climb and be up as high as possible, and they don’t care if that means ruining your screen door in the process or getting fur all over the kitchen counters. They prefer to be able to see their whole territory from up high, but it’s also in their instincts to climb for avoiding predators.

Cat climbing curtains
Image by isumi/iStock

Plus, not only does climbing give cats a great vantage point over their territory, it also increases the area of their territory. Just think of your cat getting up on the bookshelf and thinking to itself, “Everything the light touches is my kingdom.”

39. The butt sniff

One of the grosser dog behaviors, from our perspective, is when they smell each other’s butts. But view it from the dog’s perspective and it isn’t quite so nasty, since they’re basically just introducing themselves to each other. On either side of the dog’s butt are glands that secrete a variety of chemicals.

Dogs sniffing butts behavior why
Image by Memitina/iStock

These glands tell the sniffer about the gender and reproductive status of the dog, plus things about its diet, health, and emotional state. Dogs can smell 10,000 to 100,000 times better than humans, so they communicate using these chemical signals (aka smells). Dogs actually have an organ in their nose exclusively for smelling chemical communication.

40. Chewing and destruction

Chewing is one of the most annoying things dogs do, but it can have a variety of reasons. For puppies, it can relieve any pain they have from their incoming adult teeth. For adults, it keeps their teeth clean and jaws strong. But if your pup only chews when you’re not home, she might be having separation anxiety.

Dog chewing shoes behavior why
Image by K_Thalhofer/iStock

If your dog likes to lick and chew fabrics, she might have been weaned from mom too early. But there’s also the chance that your dog is chewing things because she’s hungry and wants more food. Wild dogs love to chew on bones for fun, stimulation, and to relieve anxiety, so it’s important to provide your pet dog with things to chew on.