Dogs and humans all over the world have been enjoying a mutually beneficial best friendship for perhaps tens of thousands of years. They’re the first animals we domesticated, and have been constant companions ever since. Sometimes dogs have a job they help us with, like sheep herding or duck hunting. But others are literally just here for the cuddles, and dog people are happy to oblige.

Even after all those years, we’re still learning about dogs, including more about how our unlikely animal friendship began. But plenty of dog questions have delightful answers — like whether they dream, how they learn their names, and why they slobber all over us. These seven dog facts will send you running to cuddle your closest very good boy (or girl).

How Did Dogs Evolve From Wolves?

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Today’s domesticated dogs evolved from majestic, wild wolves, but looking at a tiny, trembling chihuahua, it can be hard to imagine how that even worked. It took a really long time, especially for breeds that seem very distant from their ancient grandparents.

Scientists still don’t know exactly how those first wolves befriended humans, but it appears to have happened at least 15,000 years ago. A study of ancient wolf genomes published in 2022 found that dogs may have been domesticated twice, once in Asia and once in the Middle East or nearby, with the populations subsequently intermingling. But the evidence is far from conclusive, and dogs may have been domesticated just once, in Asia, and then later bred with wolves that lived in or around the Middle East. Regardless, most scientists now agree that dogs evolved from gray wolves.

The exact mechanism is still unclear. Wolves, after all, are pretty dangerous, and scientists are still scratching their heads about what prompted humans to feel safe around them in the first place. Regardless, your people-pleasing golden retriever is a pretty far cry from its lupine ancestors. (Your shih tzu, on the other hand, might be closer than you think.)

Do Dogs Dream?

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If you’ve spent a lot of time around dogs, you’ve probably seen them twitching or kicking in their sleep. It’s hard to know exactly what’s going on in a dog’s mind, but they do exhibit brain wave patterns much like we do when we’re in our most dream-heavy phase of sleep.

So what do dogs dream about? In one study, scientists removed or deactivated the part of the brain that keeps dogs from moving around in their sleep (yikes). These dogs started to move when they entered the dreaming stage of sleep, and began acting out their dreams, doing breed-specific behaviors. According to dog psychology researcher Stanley Coren, “What we've basically found is that dogs dream doggy things. So, pointers will point at dream birds, and Dobermans will chase dream burglars.” This indicates that dogs probably just dream about their everyday actions.

Why Are Some People Allergic to Dogs?

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Around 10% to 20% of humans are allergic to cats or dogs. There’s a common misconception that people allergic to furry friends are allergic to the fur itself, but they’re actually allergic to proteinsfound in skin cells, saliva, and urine — so if you’re allergic to dogs, you might still be allergic to a hairless dog. When someone allergic to dogs is exposed to those proteins, as with other allergies, their immune system reacts as if the substances are harmful.

Some dogs are marketed as “hypoallergenic,” but there’s really no breed that’s guaranteed to not trigger allergies. It is possible, however, that someone can be more allergic to one dog than another. The best way to figure out whether you’re allergic to a specific dog is just to spend time around it, so starting out by fostering a pup before committing to a long-term companion might be the way to go.

How Do You Convert Human Years to Dog Years?

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For decades, people have used the phrase “dog years” to compare stages in dogs’ lives to similar stages in human lives — such as whether they’re children, teens, adults, or seniors. There’s a common misconception that one human year is equivalent to about seven dog years, but it’s not all that simple.

According to the American Kennel Club (AKC), a 1-year-old medium-sized dog is roughly equivalent to a 15-year-old human. The second year of that dog’s life is around nine human years, and after that, each year is about five years. This varies from dog to dog, though, especially since large dogs tend to age faster than smaller dogs. The AKC estimates that a smaller dog, like a Pomeranian, is around age 56 after 10 years, while a very large dog, like a Great Dane, would be more like 79.

Why Do Dogs Lick People?

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Dogs licking people is often interpreted as a sign of affection, and it very well might be. Some wild dog species lick their pack members to welcome them home, and it can absolutely mean that your dog is happy to see you.

That’s not the only reason your dog might lick you, though. You could just taste really good, especially if you just finished a meal. It could also be a combination of the two: Licking may have started as a food-seeking behavior and evolved into a sign of affection. It could also be a sign of submission.

Obsessive licking, however, can be indicative of a larger problem like allergies, boredom, or pain — so if you’re worried about what it might mean, it’s worth a trip to the vet to check it out.

Can You Change a Rescue Dog’s Name?

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So you’ve fallen in love with a rescue dog, but its name is Supercalifragilisticexpialidocious. You can’t exactly be expected to shout that across the dog park. Fortunately, it’s perfectly fine to change a dog’s name after adoption. In some cases, the dog got that name at the shelter and hasn’t even had it for very long — but you can change it even if the dog’s had the name for years.

If you do decide to change your new friend’s name, it just requires a little consistency and patience. You may have to use their old name a couple of times along the way, but with plenty of positive reinforcement, your dog should fully accept their new moniker. Don’t worry — they won’t be offended!

Can Dogs See Color?

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Some dog senses are more amplified than those of humans. Most dogs can hear high-pitched frequencies that are completely silent to us, and with a sense of smell that may be up to 10,000 times more powerful than ours, they take in much more of the world via scent than sight. But how does their vision measure up?

While sight varies among both individual humans and dogs, a typical dog can see fewer colors than a typical human — but contrary to popular belief, they don’t see in black and white. They can also see yellows, blues, and combinations of the two. It’s similar to a human being who has red-green color blindness.

Dogs may still have one vision advantage over humans, though: Their eyes are better adapted to see in the dark.