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12 Ferocious Facts About King Cobras

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One of the most feared and revered snakes on the planet, the king cobra is renowned for its imposing size and deadly bite. But it also has plenty of other unique qualities: a distinctive voice, remarkable nesting habits, and a name that obscures its true identity.

1. THE KING COBRA IS THE LONGEST VENOMOUS SNAKE IN THE WORLD.

This native of south and southeast Asia normally grows to be somewhere between 10 and 13 feet long, but the biggest ever recorded was an individual from modern-day Malaysia living at the London Zoo in the mid-20th century. From end to end, the animal measured 18 feet, 9 inches long.

2. TECHNICALLY, THEY AREN’T TRUE COBRAS.

Despite that common name, king cobras are not classified as true cobras, which belong to the genus Naja. The king cobra is the sole member the genus Ophiophagus; genetic evidence suggests that these big snakes are more closely related to the mambas of sub-Saharan Africa than to true cobras.

Physically, there are many things that set king cobras apart from true ones: Kings have proportionally narrower hoods than Naja species do; Ophiophagus’s head is larger relative to its body size; and at the base of the neck, king cobras have a pair of matching, elongated occipital scales, which are absent in Naja cobras.

3. THEY GROWL.

When threatened, king cobras spread their hoods to make themselves look bigger and raise their heads as high as 6 feet off the ground. But those aren't the only threatening tools in their arsenal: They also use sound to intimidate. Threatened kings take a deep breath and then rapidly exhale, forcing a burst of air through the tracheal diverticula in their respiratory tract which acts like a resonating chamber, resulting in a sound that one scientist compared to the growl of “an angry German shepherd.” It's much scarier than your standard issue hiss.

4. THEIR VENOM ATTACKS THE NERVOUS SYSTEM.

Drop for drop, king cobra venom is less potent than that of some smaller snakes, such as Australia’s inland taipan. But when it comes to toxic chemicals, quantity can trump quality: With a single bite, a king cobra can inject as much as 7 milliliters of venom—almost enough to fill 1.5 teaspoons—into its victim.

Different venoms do different things to the human body. Many vipers, for example, have venom that targets the victim’s circulatory system, destroying red blood cells as it spreads. But the venom of a king cobra inhibits communication between nerve cells, which can cause extreme dizziness, blurred vision, and—often—paralysis. Unless the right antivenom is administered quickly, a human bite victim can die within 30 minutes. Their venom is powerful enough that a single bite can kill a 12,000-pound elephant in just three hours.

5. THEY MOSTLY EAT OTHER SNAKES.

Most true cobras have a varied diet that may include lizards, birds, rodents, and fish. But the king cobra almost exclusively dines on other serpents, a fact that’s reflected in its genus name: Ophiophagus means “snake-eater.” They're equal opportunity eaters, devouring harmless rat snakes as well as venomous kraits, various true cobras, and other kings. Not even pythons are safe (although king cobras apparently can’t swallow constrictors that exceed 10 feet in length). King cobras will also eat eggs and the occasional monitor lizard.

6. MALES WRESTLE.

Like many other species of animal, male king cobras fight over females during breeding season. First, the snakes size each other up, raising their heads as high as 4 feet off the ground. Then, they wrestle. Bodies intertwined, the snakes try to pin one another to the ground. (There's no biting involved—these snakes are largely immune to their own venom.) When one of the participants is finally pinned, he leaves.

7. SCIENTISTS SEQUENCED THE KING COBRA GENOME.

In 2013, an international scientific team sequenced the Ophiophagus genome [PDF], which revealed that the animal's venom glands can trace their evolutionary origins to the pancreatic system. The team also concluded that the snake’s deadly venom was developed during an eons-long “arms race” with prey items: Over many generations, these would-be victims grew increasingly immune to the snake’s chemical cocktail, so cobra venom evolved to be more and more dangerous as time went by (which is why, despite the fact that the snakes don't eat elephants, their venom is strong enough to kill one). “Our results," the scientists wrote in the paper, " ... provide a unique view of the origin and evolution of snake venom.”

8. KING COBRAS ARE MAINLY ACTIVE DURING THE DAY.

While many true cobras are crepuscular, king cobras snakes are diurnal, meaning they're most active during daytime. After sunset, they take shelter under logs, buttress roots, or termite mounds.

9. THIS IS THE ONLY SPECIES OF SNAKE IN THE WORLD THAT BUILDS NESTS.

Snakes, by human standards, are not model parents: 70 percent of snake species lay eggs, usually in a convenient hole or crevice, and many will abandon their clutches immediately. But the king cobra is an exception. The reptile builds a nest. First, the female gathers leaves, using her coils as a makeshift rake. After she lays 20 to 30 eggs in the middle, she gathers more leaves, layering them over her clutch (the decomposition of the leaves helps keep the eggs warm). The process can take four full days to complete, after which the female curls up on top of the nest for the next two or three months until the eggs begin to hatch. Females don't eat the entire time they're guarding the nest and are unusually aggressive, lashing out at pretty much anything that comes too close—but just before the eggs hatch, they take off.

10. BABIES—AND SOME ADULTS—ARE BANDED.

At birth, baby king cobras are just around a foot long and, with alternating black and whitish-yellow bands running the length of their bodies, are more vibrantly-colored than adults. As they grow up, most snakes gradually lose the bands; when fully grown, king cobras have an almost solidly-brown or olive color scheme (though the snakes do have faded yellow bellies). But not every snake goes solid: In Myanmar, adult kings tend to remain banded.

11. THESE SNAKES CAN LIVE TO BE OVER 20 YEARS OLD.

In captivity, the king cobra’s average lifespan is 17.1 years; 22 is the oldest verified age for this species.

12. KING COBRAS ARE GREAT CLIMBERS AND DECENT SWIMMERS.

While kings do most of their hunting on solid ground, they can often be found hanging out in trees and will occasionally stalk their prey high above the forest floor. One individual which had been fitted with a tracking device pursued a pit viper up into the canopy of a south Indian forest, climbing more than 65 feet off the ground in the process [PDF]. And while no one would describe them as semiaquatic snakes, king cobras have been known to swim for short distances.

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Penn Vet Working Dog Center
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Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.

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Animals
15 Confusing Plant and Animal Misnomers
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People have always given names to the plants and animals around us. But as our study of the natural world has developed, we've realized that many of these names are wildly inaccurate. In fact, they often have less to say about nature than about the people who did the naming. Here’s a batch of these befuddling names.

1. COMMON NIGHTHAWK

There are two problems with this bird’s name. First, the common nighthawk doesn’t fly at night—it’s active at dawn and dusk. Second, it’s not a hawk. Native to North and South America, it belongs to a group of birds with an even stranger name: Goatsuckers. People used to think that these birds flew into barns at night and drank from the teats of goats. (In fact, they eat insects.)

2. IRISH MOSS

It’s not a moss—it’s a red alga that lives along the rocky shores of the northern Atlantic Ocean. Irish moss and other red algae give us carrageenan, a cheap food thickener that you may have eaten in gummy candies, soy milk, ice cream, veggie hot dogs, and more.

3. FISHER-CAT

Native to North America, the fisher-cat isn’t a cat at all: It’s a cousin of the weasel. It also doesn’t fish. Nobody’s sure where the fisher cat’s name came from. One possibility is that early naturalists confused it with the sea mink, a similar-looking creature that was an expert fisher. But the fisher-cat prefers to eat land animals. In fact, it’s one of the few creatures that can tackle a porcupine.

4. AMERICAN BLUE-EYED GRASS

American blue-eyed grass doesn’t have eyes (which is good, because that would be super creepy). Its blue “eyes” are flowers that peek up at you from a meadow. It’s also not a grass—it’s a member of the iris family.

5. MUDPUPPY

The mudpuppy isn’t a cute, fluffy puppy that scampered into some mud. It’s a big, mucus-covered salamander that spends all of its life underwater. (It’s still adorable, though.) The mudpuppy isn’t the only aquatic salamander with a weird name—there are many more, including the greater siren, the Alabama waterdog, and the world’s most metal amphibian, the hellbender.

6. WINGED DRAGONFISH

This weird creature has other fantastic and inaccurate names: brick seamoth, long-tailed dragonfish, and more. It’s really just a cool-looking fish. Found in the waters off of Asia, it has wing-like fins, and spends its time on the muddy seafloor.

7. NAVAL SHIPWORM

The naval shipworm is not a worm. It’s something much, much weirder: a kind of clam with a long, wormlike body that doesn’t fit in its tiny shell. It uses this modified shell to dig into wood, which it eats. The naval shipworm, and other shipworms, burrow through all sorts of submerged wood—including wooden ships.

8. WHIP SPIDERS

These leggy creatures are not spiders; they’re in a separate scientific family. They also don’t whip anything. Whip spiders have two long legs that look whip-like, but that are used as sense organs—sort of like an insect’s antennae. Despite their intimidating appearance, whip spiders are harmless to humans.

9. VELVET ANTS

A photograph of a velvet ant
Craig Pemberton, Wikimedia Commons // CC BY-SA 3.0

There are thousands of species of velvet ants … and all are wasps, not ants. These insects have a fuzzy, velvety look. Don’t pat them, though—velvet ants aren’t aggressive, but the females pack a powerful sting.

10. SLOW WORM

The slow worm is not a worm. It’s a legless reptile that lives in parts of Europe and Asia. Though it looks like a snake, it became legless through a totally separate evolutionary path from the one snakes took. It has many traits in common with lizards, such as eyelids and external ear holes.

11. TRAVELER'S PALM

This beautiful tree from Madagascar has been planted in tropical gardens all around the world. It’s not actually a palm, but belongs to a family that includes the bird of paradise flower. In its native home, the traveler’s palm reproduces with the help of lemurs that guzzle its nectar and spread pollen from tree to tree.

12. VAMPIRE SQUID

Drawing of a vampire squid
Carl Chun, Wikimedia Commons // Public Domain

This deep-sea critter isn’t a squid. It’s the only surviving member of a scientific order that has characteristics of both octopuses and squids. And don’t let the word “vampire” scare you; it only eats bits of falling marine debris (dead stuff, poop, and so on), and it’s only about 11 inches long.

13. MALE FERN & LADY FERN

Early botanists thought that these two ferns belonged to the same species. They figured that the male fern was the male of the species because of its coarse appearance. The lady fern, on the other hand, has lacy fronds and seemed more ladylike. Gender stereotypes aside, male and lady Ferns belong to entirely separate species, and almost all ferns can make both male and female reproductive cells. If ferns start looking manly or womanly to you, maybe you should take a break from botany.

14. TENNESSEE WARBLER

You will never find a single Tennessee warbler nest in Tennessee. This bird breeds mostly in Canada, and spends the winter in Mexico and more southern places. But early ornithologist Alexander Wilson shot one in 1811 in Tennessee during its migration, and the name stuck.

15. CANADA THISTLE

Though it’s found across much of Canada, this spiky plant comes from Europe and Asia. Early European settlers brought Canada thistle seeds to the New World, possibly as accidental hitchhikers in grain shipments. A tough weed, the plant soon spread across the continent, taking root in fields and pushing aside crops. So why does it have this inaccurate name? Americans may have been looking for someone to blame for this plant—so they blamed Canada.

A version of this story originally ran in 2015.

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