The human body

Bathtubs of snot? The "gross but true" guide to human anatomy

Image: Tima Miroshnichenko

From the tiny, unseen creatures residing on your eyelashes to the incredible volume of mucus your nose produces annually, the inner workings of our anatomy are packed with crazy facts that sound like science fiction. Prepare to have your mind blown as we discover 10 of the most astounding, hard-to-believe truths about our very own body. Get ready to never again look at your saliva, bones, or even your earwax in the same way!

Image: César Couto

Did you know that about 50% of people have tiny creatures living on their eyelashes? These eyelash mites are about a third of a millimetre long. They can sometimes cause allergic reactions, but most people never find out they’ve got them. We bet you're calling your ophthalmologist for a consult right now!

Image: Franco Antonio Giovanella

Earwax is produced by your body to protect the lining of your ear canal by trapping dirt and repelling water. But what will probably baffle you is that by the time it reaches the outer ear, the wax has been inside your ear for about a month. No wonder it tastes so disgusting!

Image: Andrea Piacquadio

You usually only notice snot when you’re making too much of it, that is, when you are sick. But can you guess how much mucus an average person produces in a year? The answer will shock you: about 100 gallons, enough to fill two bathtubs! While the sticky goo is rather unpleasant, you wouldn’t want to go without it. Mucus creates a layer of protection between you and the outside world, so thank God it’s there.

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And what about your saliva? How many bathtubs do you think you can fill with your year's supply? Saliva helps break down and swallow food, fights bacteria, and neutralizes acid, among many benefits. So, if it is that good for you, it’s no surprise your mouth produces tons of it. In fact, it makes between 250 and 730 quarts a year, equivalent to filling a small swimming pool over a lifetime.

Image: BUDDHI Kumar SHRESTHA

That pink squidgy blob inside your head is stuffed with facts, memories, and dreams. Your brain is constantly crackling with tiny pulses of electricity, performing ten quadrillion calculations per second. They’re brilliantly complicated machines that scientists are only just beginning to understand. One thing is for sure: an average person has 1460 dreams in a year, about four dreams every night, or to put it another way, around the same as the number of miles from Denver to Nashville.

Image: camilo jimenez

Clever as your brain is, it wouldn’t be able to do much without the network of nerves that link it to the rest of your body. Nerves bring information from your senses to your brain and deliver orders from your brain to the other organs. As you can imagine, if we were to measure that amazing network, we would end up with a lot. In fact, every person has a whopping 44 miles of nerves running through their skin. Can you imagine?

Image: Ximena Mora

The outer layer of your skin is called the epidermis and consists of dead cells that provide protection from dirt and germs. What you probably didn’t know is that your body is constantly losing and replacing these cells. Also, your dead skin cells sometimes absorb water and swell. This is the reason the ends of your fingers go wrinkly in the bath. But don’t worry, the entire surface of your skin is replaced every month.

Want to play some more? How much do you think the average adult’s skin weighs? Just under 7 pounds, or as we like to say, the same as three pineapples!

Image: Ashton Bingham

Human hair feels soft, but it’s one of the strongest fibres on the planet. The number of hairs on your head ranges from around 9,000 to 140,000, depending on what sort of hair you have.

Everyone loses about 50 to 100 hairs every day, but this process can speed up in men as they get older. Hair generally grows about half an inch a month, or 6 inches a year. Yet, if you don’t cut it regularly, it will most likely stop growing when it’s about 5 feet long.

Image: cottonbro studio

This fact is not for skeptics: the average adult’s skeleton weighs the same as one car tyre. In fact, our skeleton only makes up about 15 per cent of our overall body weight. So, next time someone tells you that big bones is the reason for them being overweight, be suspicious.

Another fun fact? Your collarbone is the last of your bones to stop growing when you become an adult. Called the clavicle, it doesn’t stop growing until you’re about twenty-five.

Image: The Lazy Artist Gallery

Human muscles, on the other hand, make up about 40% of your body weight, and there are more than 600 of them. Yet, you use just 200 when you take a step, and almost all of them when you throw a ball.

The biggest muscle in your body is the _gluteus maximus_—a.k.a your bum. The smallest is in your ear, the stapedius, just about forty thousandths of an inch. The jaw muscle is the strongest by force, and the eye muscles are the busiest—10,000 movements an hour when reading! Our favorite muscle, though? The heart, of course!

The 12 longest-living animals on Earth (and how they cheat time)

Nature doesn’t just create beauty, it crafts survival miracles. While most animals have short lives, a rare few have mastered the art of staying alive for centuries, even millennia. These aren’t just long-lived creatures; they’re nature’s ultimate time travelers. From the frozen depths of the oceans to the darkest corners underground, they’ve developed bizarre, brilliant strategies to cheat death. Get ready to meet 12 animals whose lifespans will absolutely blow your mind.

Record age: up to 15,000 years

This unassuming sea sponge thrives in the freezing waters of Antarctica, where temperatures hover around 28.6 °F—so cold that biological processes hit the brakes. In such icy conditions, metabolism slows to a crawl, allowing these sponges to live for thousands of years.

Some have reached impressive sizes of over 3 feet tall and have been around since mammoths were still thundering across the tundra. They don’t move, they don’t stress, and they barely change, just quietly existing while centuries pass them by. Their secret to extreme longevity? Glacial patience, deep-sea stillness, and a lifestyle that redefines "low-maintenance".

Age: technically… infinite

This tiny jellyfish, no bigger than a fingernail—less than 0.2 inches—is like the ocean’s very own Benjamin Button. What makes it truly extraordinary is its ability to rewind its life story, flipping back to a youthful, juvenile stage whenever it wants. While it’s not completely invincible (predators and other threats are still very real), if left undisturbed, it can keep hitting the reset button on aging indefinitely, making it one of the most fascinating "time-benders" in nature.

Record age: 507 years

In 2006, a special clam was discovered buried deep in the seabeds of the North Atlantic. Scientists were able to determine that it had been there since at least 1499—that’s centuries before the United States was even a thought! This ancient marvel, nicknamed "Ming", was able to perfect a slow-and-steady approach to life. Growing at a snail’s pace and barely budging, Ming’s sedentary lifestyle turned out to be a brilliant strategy for beating the clock. Who knew doing almost nothing could be the ultimate secret to longevity?

Record age: estimated 392 years

These sharks aren’t your average ocean cruisers—they can stretch over 20 feet long and weigh up to 2,200 pounds. But what’s really mindblowing is how slowly they move, like they’re in a permanent state of deep relaxation. Living in the icy Arctic waters, these giants don’t hit adulthood until they’re about 150 years old, and some can glide through the depths for nearly 400 years. Imagine that! These ancient swimmers were already around before America declared independence... and they are still out there, silently roaming the seas!

Record age: over 211 years

This whale is a true ocean giant, stretching up to 60 feet long and weighing a staggering 200,000 pounds. But what makes it stand out isn’t just its size but its age. Some of these majestic creatures carry harpoons from the 1800s still lodged in their skin, like walking history books. Just picture living so long that you’re literally carrying outdated technology embedded in your body—talk about being a time traveler of the seas!

Record age: 200 years

Spanning the chilly Pacific coastline from California all the way up to Alaska, this spiky little ball—about 7 inches across—is full of surprises. It munches on algae and calls the deep, dark ocean its home, thriving at depths of up to 300 feet. Don’t let its size fool you: this prickly creature is a true elder of the cold seas, quietly outliving many ocean neighbors while keeping a low profile. A tough, slow-living veteran wrapped in spikes!

Record age: 226 years

Meet Hanako, a legendary Japanese koi who swam through life for an astonishing 226 years. Scientists discovered how old she was by studying the rings on her scales, much like counting the growth rings of a tree. These colorful, ornamental fish aren’t just symbols of good fortune; they’re also secret long-lifers with the potential to celebrate over two centuries of birthdays, as long as they get the right care and a peaceful pond to call home.

Record age: 190 years

Jonathan is a male tortoise living on the remote island of Saint Helena in the South Atlantic Ocean. He was born back in 1832, and he’s still happily chomping lettuce and soaking up the sun today. Weighing in at more than 400 pounds and measuring around 3 feet long, Jonathan holds the title of the oldest known living land animal on the planet. If he could share tales, they’d span nearly two centuries of history. Imagine that!

Record age: 152 years

This ancient-looking fish, with its whisker-like barbels, looking like a tiny underwater submarine, prowls the lakes of North America. It can reach an impressive length of up to 7 feet and weigh around 200 pounds. These slow-living creatures don’t rush into adulthood—they start breeding only around age 20—and then take their time cruising through life at a leisurely pace. Believe it or not, one legendary catch in Wisconsin was estimated to be over 150 years old!

Record age: over 90 years

This chunky, night-loving parrot from New Zealand is a true oddball—it can’t fly, snores like a grumpy grandpa, and smells like fresh flowers. Despite its quirks, this bird boasts an impressively long lifespan. Sadly, it teeters on the edge of extinction. The oldest known kakapo, affectionately named Richard Henry, lived 90 years, earning him the title of the charmingly eccentric elder statesman of the avian world.

Record age: 37 years

This tiny, kooky rodent—barely 3 inches long and just over an ounce in weight—could’ve been cast straight from a sci-fi apocalypse flick. Dwelling in vast underground colonies across Africa, it’s practically invincible to cancer, pain, and the usual effects of aging. Scientists are fascinated by this little marvel, even if it’s not winning beauty contests anytime soon. Its superpowers make it a star in longevity research!

Record age: estimated 100+ years

Lobsters have a totally different rulebook than us when it comes to aging. They don’t really grow old; they just keep getting bigger and bigger. Some giant lobsters weigh over 40 pounds and stretch beyond 3 feet long. Their biggest threats? Not old age, but predators or the risky process of shedding their shells. In theory, they could live forever if left alone—but let’s be honest, not many get to enjoy a peaceful, lobster-sized retirement!