A hairy business

Let your hair down: 10 amazing facts about human hair

Image: Ali Pazani

The human body is incredible, from its mechanics to its ability to heal and adapt to multiple environments and situations. Hair, as part of our body, is no exception to this complexity and wonder. Let’s take a look at 10 amazing facts about our hair that you may not know!

Image: Ian Talmacs

The word hair is used to describe two separate and distinct components: the follicle and the shaft. The follicle—what we commonly refer to as the root—is a living organ located in the dermis of the scalp. It’s responsible not only for growing hair but also for helping regenerate skin after a wound.

On the other hand, the shaft—often referred to as the strand—is a filament composed of layers of keratin, the same protein that makes up our nails. Unlike the follicle, the hair shaft is technically dead because it consists of dead cells.

Image: Joyful Bird

Each hair strand is composed of three layers. The innermost layer is the medulla, and even scientists are still uncertain about its exact function. Surrounding the medulla is the cortex, which absorbs water and provides strength to the strand. The cortex also contains melanin, the pigment that determines hair color, and its shape plays a major role in whether hair is straight or curly. The outermost layer is the cuticle, which serves primarily to protect the hair shaft.

Image: Tyler McRobert

Hair color is primarily influenced by several genes, including MC1R, which plays a key role in melanin production. However, not everyone produces the same type or amount of melanin. Higher amounts of melanin result in black hair, while varying levels and types of melanin—along with genetic variations—produce brown, blond, and other shades.

Red hair, the rarest natural color, is caused by a mutation in the MC1R gene and is inherited in a recessive pattern. This means a person must inherit two copies of the mutated gene (one from each parent) to have red hair, though many people carry the gene without expressing the trait.

Image: William Warby

Growing at a rate of about 0.2 to 0.5 inches per month, hair is the second-fastest growing tissue in the human body—surpassed only by bone marrow. This rate is influenced by factors such as genetics and ethnic background. Other variables, such as age, lifestyle, or health, can also have an impact on our hair growth and density.

Image: Sohan Rahat

We usually think of cats or dogs when it comes to shedding, but humans also shed hair regularly. After all, hair is a trait shared by all mammals. The average person sheds between 50 and 100 strands of hair per day, though this number can increase in response to stressors such as illness, hormonal changes, or emotional stress. Once the stress subsides and the body readjusts, the excess shedding typically stops.

Image: Joseph Chan

Commonly associated with aging, grey hair isn’t a color in itself but rather the result of a loss of pigment. As part of the natural aging process, melanin production in the hair follicle gradually decreases and eventually stops, causing strands to appear grey or white.

Genetics and ethnic background play a major role in determining when and how the greying process begins. Some people are even genetically predisposed to start greying at a very young age.

Image: Jaroslav Devia

Hair texture is commonly associated with ethnic background, but that’s not the only factor involved. Texture is primarily determined by genetics, and while genetics are closely tied to ancestry, all hair textures can be found across different populations.

Scientists believe that hair texture—specifically curl pattern and volume—is a result of the shape of the shaft. A round shaft typically produces straight hair, while flatter or more oval-shaped shafts tend to create curls and waves.

Image: Amritanshu Sikdar

Depending on the structure of your hair cuticle, your hair may be more or less water-repellent. Hair shafts with a more porous cuticle absorb water easily but also lose moisture quickly. In contrast, shafts with a tighter-packed cuticle struggle to get wet and are slow to dry.

Image: Sonja Langford

Hair doesn’t grow continuously or all at once—each strand follows a cycle with distinct phases. First comes the growing phase, which varies depending on the type of hair (for example, facial hair grows faster and for a shorter period than scalp hair). Eventually, growth slows down, and the strand detaches from the root.

After this, the hair enters a resting phase, during which it remains in place until it is naturally shed. At any given time, we have hairs in all stages of this cycle, which is why we regularly shed hair without going bald.

Image: Hans Reniers

Like any other part of the body, hair contains DNA and genetic material, which means a person can be genetically identified from a single strand, provided it includes the root. But hair holds even more information. The analysis of a hair strand can reveal substances that were present in a person’s bloodstream over time, including vitamins, minerals, medications, alcohol, and other substances.

Names that lie

Mountain chickens are frogs? 10 animals with misleading names

Some animals have commonly been given names that might lead you to believe false things about them. For example, as we all know, guinea pigs are not pigs, sea horses are not horses, and starfish are neither stars nor fish. So, how did these names come to be? While lookalike allegations may justify some, others are simply far-fetched. Is there any truth or reason behind these inaccurate nicknames—like "firefly"? Let’s explore 10 animal names that are, arguably, misnomers.

Let’s start with one of the most far-fetched names on this list. Mountain chickens aren’t birds at all—they’re large frogs. And they don’t live in mountains, either. These frogs are found mostly in the Caribbean, inhabiting lowland rainforests and swamps. A more accurate and realistic name for them is "giant ditch frogs," which refers to their large size and their tendency to dwell near water bodies.

So, how did they get this name? The story goes that locals found the frog’s meat similar in taste and texture to chicken. Yes, this now critically endangered species was once considered a delicacy in local cuisines.

You would think that the red panda is just a smaller, red version of the giant panda. After all, they share cute faces, patches around their eyes, and similar snouts and ears. But you’d be wrong—red pandas are not bears.

Here’s the explanation: The word "panda" is believed to derive from the Nepali word ponya, which refers to animals with claws adapted for eating bamboo. This is the biggest trait red and giant pandas have in common: their heavily bamboo-based diets. Red pandas, sometimes nicknamed "firefoxes," belong to a mammal family of their own and are more closely related to skunks than to giant pandas.

Titmouses aren’t rodents—did you know? Instead, they are songbirds known for their gray or bluish-gray feathers. One of the most common species is the tufted titmouse, and you’ll be pleased to know that the plural form is, indeed, "titmice."

The name "titmouse" comes from Old English, where tit referred to a small creature, and mase was a general term for a bird. Over time, mase became obsolete, and "titmase" was transformed into "titmouse" due to the similarity between the words. Arguably, there’s also some physical resemblance between the gray color and beady, round eyes of both titmice and mice.

Yes, the name "electric eel" is misleading—but not for the reasons you might think. These aquatic animals are indeed capable of generating shocks of electricity, up to ​​860 volts, which they use to stun their prey or defend themselves. However, strictly speaking, they are not eels.

Unlike true eels, which belong to the family Anguillidae, electric eels are part of the knifefish family and are more closely related to catfish. Early European explorers misnamed them based on their elongated, eel-like bodies.

Seahorses are fish, just like salmon or clownfish. Arguably, they look nothing like those species. Instead, for centuries, humans have noticed their resemblance to horses. Seahorses have a distinctive upright swimming posture, elongated heads and necks, and a caudal fin that even resembles a horse’s mane.

Their scientific name, Hippocampus, is borrowed from the Ancient Greek word hippókampos. Interestingly, the term didn’t originally refer to this animal but to a mythological marine creature. In Greek, hippos means "horse," and kampos means "sea monster."

Guinea pigs aren’t pigs—nor are they from Guinea, the West African country. Instead, they are rodents native to South America. By now their name has become synonymous with "experiment subject" because of how frequently they were used in scientific research.

There are a couple of theories behind their misleading name. The "pig" part likely comes from the squealing noises they make, which resemble those of piglets. As for "guinea," it might derive from the British coin of the same name, implying they were sold for its equivalent value. Another theory is that European sailors, associating distant Guinea with anything exotic, mistakenly applied the name to these South American rodents.

The koala is often called a "koala bear," but it’s not a bear at all. European settlers in Australia gave it this name because its round face and fluffy ears reminded them of bear cubs.

Koalas are, in fact, marsupials. Like kangaroos, they carry their young in pouches. The word koala comes from the Dharug language (an Aboriginal language of Australia) and is believed to mean "no water," referring to the koala's ability to survive on eucalyptus leaves with minimal water intake. Did you know? Eucalyptus leaves are low in nutrients and mildly toxic. As a result, koalas have a slow metabolism and sleep up to 20 hours a day.

Fireflies don’t handle fire. They do, however, possess the ability to produce light, a phenomenon called bioluminescence. This light creates the illusion of tiny flames flying through the night. No wonder they have been associated with magic and fascination for centuries.

Despite their name, fireflies aren’t flies—they’re beetles. They produce light through a chemical reaction in their abdomens, which they use to attract mates or communicate. In fact, ​​different firefly species flash in distinct rhythms to help them identify each other.

The first time you hear the term "prairie dogs," you might picture packs of dogs roaming freely across the prairies. In reality, these animals are rodents and belong to the ground squirrel family.

The name is believed to have been given by early European settlers due to their high-pitched sounds. Prairie dogs are capable of producing sophisticated and varied calls to communicate with one another, sometimes sounding like man’s best friend. The "prairie" part of their name comes from their habitat—vast grasslands and prairies across North America. These rodents are expert burrowers and typically live in small family groups called "coteries," where members groom and protect each other.

It’s not only that ladybugs aren’t all female—they aren’t truly bugs, either. Instead, they are a type of beetle. These round and colorful insects have been widely associated with good luck and fortune for centuries. The reason for this has to do with the story behind their nickname.

The name "ladybug" originated in the Middle Ages, when farmers prayed to the Virgin Mary for help with pests in their crops. The beetles, which helped control aphid populations, were called "Our Lady's birds" or "Our Lady's beetles," later shortened to "ladybirds" or "ladybeetles." Over time, much to the frustration of entomologists, this evolved into the popular term "ladybugs."