Since dogs and wolves still share similar enough DNA, they are capable of mating and breeding pups. Called Wolfdogs, there are an estimated 300,000 in the United States.

Many pet owners have said their dog may smell like popcorn or Fritos. Believe it or not, that smell has nothing to do with their diet. It’s actually bacteria growing on their paws.

In most of the animal kingdom, size has been correlated with longevity but not so in dogs. Scientists have been baffled about why smaller dogs tend to live longer. Some think larger dogs grow faster as puppies and may develop diseases because of it. Small dogs live from 10 to 15 years, medium sized dogs 10 to 13, and large dogs 8 to 12 years.

Like humans, dogs have both an upper and lower eyelid but they’ve also got a third called the nictitating membrane. It has various functions including clearing debris and mucus and producing tears.

Dogs have a great sense of smell, most people know that. However, what they might not know is some dogs can have a sense of smell 100,000 more acute than our own. They have about 300 million olfactory receptors in their noses. Humans only have 6 million.

They say a dog is man’s best friend, and there’s a lot of truth to that. Humans and dogs have evolved together from the earliest point of dog domestication 32,000 years ago. Researchers from the University of Chicago found that several groups of genes in humans and dogs have been evolving in parallel, relating to diet, digestion, neurology, and disease.

A viral video went around showing a Ta’if baboon kidnapping a puppy and supposedly keeping it as a “pet.” While baboons are known to kidnap females of their own species and even dogs, scientists have made clear they aren’t keeping them as their pets.

On hot summer days, dogs regularly open their mouths and pant to cool themselves down. The only sweat glands they have is in their paws, but it has more to do with traction than temperature.

Because a dog’s sense of smell is so strong, they can detect when we’re afraid or anxious. When we’re anxious, we perspire lightly. We can’t see it or smell it, but a dog can, telling them how we’re feeling.

Dogs have dreams just like we do when we go to sleep. If you want to see it in action, just wait 20 minutes after your dog goes to sleep. They’ll probably have their first dream at that point, and you’ll see their eyes moving behind their eyelids.

The Titanic had excellent dog facilities on board and was considered very dog-friendly. Of the twelve dogs that boarded the Titanic, only three survived – a Pekinese and two Pomeranians.

Called “halitosis,” a dog’s bad breath might be the result of periodontal disease, diabetes, respiratory problems, gastrointestinal problems, or something else entirely.

Much like our own fingerprints, the lines of a dog’s nose are unique and could identify individual dogs from each other. The Canadian Kennel Club has been using noseprints to ID dogs since 1938.

The Turnspit dog, also called “Vernepator Cur” which is Latin for “the dog that turns the wheel,” was used in 16th century Britain kitchens to run on a wheel like a hamster and to turn meat so it would cook evenly. While this breed no longer exists, some believe the closest relative could be the Welsh Corgi.

Capable of sensing the barometric pressure drop and a shift in the static electricity field, dogs have a keen sense of when a storm is coming. Dogs can also hear sounds of thunder before we hear them.

Of the 35,000 stray dogs regularly roaming around Moscow, there are a rare few who have figured out how to navigate Moscow’s complex subway system, walking onto the trains and going from A to B with their human neighbors. They’ve also been observed to obey traffic lights, and a pack of strays will send out a small cuter dog because it usually ends up getting food from humans.

In the 1860’s, San Francisco passed an anti-stray dog law to try to combat their stray problem. However, two dogs named Bummer and Lazarus were later considered exempt from this law due to their ability to catch and eat rats, another horrendous problem in San Francisco. Some accounts state the dogs were capable of killing up to 400 rats in the month of January alone.

Highly sensitive to subtle changes in air currents, a dog’s whiskers act as receptors to information such as the height, shape, and speed of nearby objects. This ability allows them to “see” in the dark.

Dogs have “anal sacs” which release chemicals providing a whole host of information for dogs to smell. With their incredible noses, they can determine the gender, diet, health, and even emotional status of the dog.

When puppies are first born, both their eyes and ear canals are shut tight. Both their eyes and ears are still developing during this fragile time and won’t open until fully developed.

Guide Dogs are incredibly well trained and are capable of eliminating on command. Trainers use different words to make this happen, like “busy busy” or “go time.” Once the dog starts to go, the person can feel its back to determine if it’s peeing or pooping. This way they know whether or not to clean up the poop.

Dogs’ amazing sense of smell has been shown to detect cancer and diabetes. During multiple studies, dogs have been intriguingly accurate in detecting cancer in breath and urine samples. They’ve also been able to detect low blood sugar; there are even service dogs called “Diabetic Alert Dogs” that can warn an owner when their blood sugar is reaching dangerous levels.

According to Live Science, based on a language development test, dogs have the intelligence of a two-year-old child. Most dogs can learn up to 165 words, similar to a two-year-old. Some of the smarter breeds of dogs can learn 250 words.

In order to complete some of their missions, Navy Seals utilize the Belgian Malinois breed. Their training is just as brutal as their human counterparts and only 1% of the candidate’s dogs make the cut. They train with their handlers at least 15 hours a week, can jump out of aircrafts with their team, and can even parachute with their handlers.

A study by the Frontiers in Zoology found that dogs are sensitive to the electrical magnetic field of the earth and like to poop on the north-south axis. They discovered this after examining 70 dogs made up of 37 breeds in a two year period. Scientists are still not sure why they do this.