Body oddities

12 creepy body facts your biology teacher definitely skipped

Image: CDC

The human body is a marvel of biology—but sometimes, it's downright disturbing. Did you know it’s possible to cry blood? Or that we have taste receptors in our stomachs? From mysterious functions to deeply unsettling facts, our bodies are full of creepy surprises hiding beneath the surface. Here are 12 weird but true insights into what’s really going on inside you.

Image: Kimia Zarifi

Unlike most body parts, ears (and noses) continue to grow as you age. It’s not just cartilage at work—gravity slowly stretches skin and tissue, making ears longer over time.

This process, sometimes called "gravity-induced elongation," only starts to become more noticeable after age 30. That’s why elderly people often seem to have larger ears, even if they were proportionate in youth.

Image: Sander Dalhuisen

Receptors similar to those on your tongue exist in your stomach and intestines. They don’t "taste" in the traditional sense, though, but detect chemical signals.

Thanks to these oddly placed "taste" receptors, our bodies help regulate digestion and appetite by detecting nutrients and potential toxins. They’re crucial for gut-brain communication and may even influence cravings.

Image: Ali Shoaee

Yes, you read that right. Your eyelashes are home to Demodex mites—tiny, spider-like creatures that feed on dead skin cells and oils around hair follicles.

It may sound like something out of a horror movie, but most people—especially adults—have them. These mites emerge at night, mate on your eyelids, and retreat by morning. They’re harmless, but still undeniably creepy.

Image: Ana Itonishvili

Your body emits a small amount of radiation due to naturally occurring elements like potassium-40 and carbon-14, which are present in body tissues.

While this natural radioactivity is harmless, it’s still measurable. A single human body can emit around 7,000 particles per second—enough to trigger some sensitive detectors.

Image: Chaozzy Lin

Called haemolacria, it’s a rare condition where blood mixes with tears. Its causes can include infections, injuries, tumors, or hormonal changes.

Though quite dramatic and certainly alarming, some cases are benign. It has been documented in both adults and children, and it is often linked to extreme stress.

Image: MJH SHIKDER

Even just walking through a room, you leave behind a cloud of genetic material—skin cells, saliva, and sweat—all rich in your DNA.

Sometimes called a "biological fingerprint," this material is enough to identify you. Law enforcement and forensic scientists can even recover DNA from air filters or dust!

Image: Robina Weermeijer

Some people are born with supernumerary organs—extra kidneys, spleens, or even, in extremely rare cases, hearts. These additional organs are often non-functional but can still be detected.

For example, an estimated 1 in 1,000 people has an extra spleen, often discovered by accident during unrelated scans or surgery.

Image: Anshita Nair

Lack of sleep triggers glial cells in the brain to break down and consume parts of synapses—literally "cleaning house" in an extreme way.

This self-cannibalization can lead to cognitive decline and has been linked to neurodegenerative diseases in chronic cases.

Image: Alessandro La Becca

Osteomas are benign bone tumors that can sometimes protrude through the skin, resembling small "horns." Most appear on the skull or jaw.

Though rare, some osteomas can grow several inches. Surgical removal is usually performed for cosmetic reasons unless the growth interferes with normal function.

Image: Ümit Yıldırım

The human mouth can harbor over 700 different types of bacteria—many more than you'd find on a toilet seat.

Most of these bacteria are harmless—and even essential for healthy bodily functions—but under poor hygiene or illness, they can cause infections, tooth decay, or even contribute to heart disease if they enter the bloodstream.

Image: Robina Weermeijer

In extremely rare cases, a type of tumor called a teratoma can develop in the lungs and contain hair, teeth, or even eye-like tissue.

Teratomas are usually benign but still quite bizarre. They form from germ cells and can grow almost any tissue type due to their stem cell origin.

Image: Harlie Raethel

Even the hardest bones in your body are porous like a sponge. Under a microscope, they reveal a honeycomb structure filled with blood vessels and bone marrow.

This structure makes bones both strong and lightweight. However, in conditions like osteoporosis, those holes widen, weakening the bone from the inside.

Planning your next adventure

Ultimate survival guide: The 10 essentials of hiking

Image: Toomas Tartes

Walking in the outdoors is excellent for our physical and mental health. And in the United States we have wonderful landscapes to make the most of this unique sport. However, while hiking is a very popular activity, it is not always practiced properly. Whether you plan to visit a National Park, venture into the woods, or explore bear country, it's best to prepare accordingly. Here are 10 pro tips to keep in mind when going hiking.

Image: Sandra Seitamaa

If you've never hiked or camped before, don't worry, it's never too late! The best thing you can do is start slowly. First, find a path near your house and do small hikes every day. Once you realize how much you love getting your body moving, choose a place you've always wanted to visit. If nothing comes to mind, go through an atlas or a book on hiking to pick the perfect place for a new adventure.

Next, you can start proper training and even join a local hiking club to learn the ropes and meet new people. Finding a buddy to share the experience with can make all the difference, —trust us, conversation helps make training more enjoyable. Now that you're all set, it's time to get ready!

Image: maxmann

Packing is probably the most important thing when you go hiking. It’s where all starts and doing it properly can make the whole trip a success or a failure. First, lay out everything you think you'll need and strategize from there. Big items go first, but remember, try to keep weight as low as possible. For example, look at the amount of clothing you plan to bring, then cut it in half. It's not a wilderness experience otherwise!

If space becomes a problem, you can get some compression sacks for slimming down puffy items, like sleeping bags or outerwear. You can also deflate dry-food packs with a pin and cover the hole with tape. Finally, put survival items in the front of the pack for fast emergency access.

Image: Pixabay

On the trail, adequate shoes make all the difference. Many people get blisters or other ailments just for choosing the wrong shoes. The best way to avoid these issues is to prepare. For starters, find shoes that are comfortable and right for your feet type. Don't order your next pair online, it’s better to visit a retail store and try on multiple pairs.

Socks are as important as shoes. Choose synthetic or wool socks that absorb moisture better for long days in the outdoors. The insoles that come in boots may not be a very good fit for your foot. The more cost-effective solution is to replace them with better ones. Also, always pack up some moleskin, duct tape, or other first-aid implements, just in case. Finally, remember to tie your boots correctly to prevent rubbing and you are good to go!

Image: Baihaki Hine

Setting up a campsite is not hard if you take some key steps. First, find a site 200 feet from a lake or a stream and choose durable surfaces whenever possible. Spend extra time searching out a sheltered location to avoid the wind. Also, look up to make sure no dead trees or branches threaten to fall on your site.

Once you’ve found the perfect spot, wait until the winds die down —often at sunset— to pitch your tent. If you can, orient the door to the east for early sun and place your tent so the smallest side faces the wind. Secure and anchor your tent properly with nylon cords and stakes and you’ll be ready to spend the night in the open.

Image: Iren Polishchuk

Where campfires are allowed, it's important to know how to build —and put out— flames properly. First of all, find fuel: an armload of twigs and sticks will get the fire going. Search for dry wood under driftwood piles. If necessary, shave off the wet bark.

The next step is to make a pit. Choose a safe place and dig a small pit surrounded by wind-breaking rocks. Place a firestarter —for example, cotton balls, egg cartons, or wine corks— on a bed of sticks leaving gaps for air to fuel the flames. Place a fist-size stack of wood shavings, twigs, and paper over your fire starter and light it up. Carefully supply larger sticks and blow on them gently to fan the flames.

Before leaving the campsite, remember to put out the fire. Use water and mix the ashes and embers with soil. Make sure it’s completely out: if it’s too hot to touch, it’s too hot to leave.

Image: ArtHouse Studio

Like wine to the gods, water is the nectar of hikers. But, how to stay hydrated during long exercise hours in the outdoors? Start the day with plenty of liquid. While you sleep, you lose as much as 1.5 pounds of fluid through sweat and respiration. In the morning, replenish with 16 to 24 ounces of water.

While trekking, don’t wait till you are dead thirsty to drink water. Instead, sip 4 to 6 ounces of liquid every 20 minutes, it'll help you feel stronger. Also, since sweat is made up of sodium and potassium, it’s important to keep an eye on electrolytes. Try to alternate water with a sports drink or munch on salty snacks. If you start feeling dizzy, have a headache, or find it difficult to concentrate, you are probably dehydrated. Set up camp: A long rest, a good meal, and lots of water will get you back on track.

Image: Diogo Tavares

If you are traveling from low to high elevation plan an extra day or two to allow your body to adjust. Avoid arriving directly to trailheads above 10,000 feet and instead plan a day hike at a lower elevation. The first couple of days try to moderate your effort. Since air is very dry at high altitudes, always stay hydrated and abstain from drinking alcohol.

Also, don't ascend more than 2,000 feet per day, and at night set camp below the highest elevation you've reached. If you develop symptoms of altitude sickness, like persistent headache, loss of appetite, fatigue, or loss of coordination, stay put. Go down if the symptoms don't improve within 24 hours.

Image: NEOM

If your hiking trip is during the summer months, you’ll have to be extra careful with the high temperatures. Always have a backup plan for your water supply and bring hard candy to suck and keep your mouth moistured.

Try to protect your body from the sun's rays. Don't wear shorts or short sleeves. Cotton clothes retain moisture better than synthetics and will keep you cooler. Wear a full-brimmed hat and extra-dark sunglasses at all times. Use sunscreen on any exposed flesh, like your face and the backs of your hands, and reapply frequently.

Don't hike during the middle of the day, when temperatures reach their peak. In open country, go from shade to shade. Move for half an hour and rest for another half. You can even hike at night and make the most of a starry sky!

Image: Andy Holmes

Let’s face it, most of North America is bear country. It’s important to take precautions when hiking near their habitats to prevent unfortunate encounters. First of all, don’t hike alone. Bears are less likely to attack groups than individuals. Also, always make noise. Given the opportunity, most bears will avoid human contact.

Storing food properly and paying attention to the terrain can give you an advantage. But even if you stay vigilant the whole time, you may come across a grizzly or a black bear. Pack bear spray or a bear bell and keep them handy. If you find yourself face to face with a bear, give it a chance to hear you and flee before their protective instincts kick in. However, if you feel you are about to be attacked, find a high tree to climb or lie face down and play dead.

Image: j.mt_photography

Forget bears, the most common and dangerous risk when hiking is a river crossing. Here's how to do it safely. Since narrow spots are deeper and faster, always cross a river at its widest point. Check your map for forks, they contain less water and are potentially easier to cross.

If you have to cross a glacial river, do it early in the day. This way, you’ll avoid the higher runoff volume that comes with afternoon melting. In fast-moving waters, cross at a slight angle, heading downstream but facing upstream. If you fall, don't panic. Remove your pack if it prevents you from getting up. If the current takes you, flip on your back and calm down. When you reach calm water, swim back to shore.