10 of the World's Strangest Spiders

Wirepec // iStock
Wirepec // iStock

All spiders have eight legs, but that’s where most of their similarities end. Scientists frequently discover new species with unexpected talents—be it a flair for cartwheels or the ability to turn itself into a disco ball. Researchers have also found plenty of specimens that are just plain weird-looking. Here’s a list of 10 fascinatingly freaky arachnids.

1. CEBRENNUS RECHENBERGI // THE FLIC-FLAC SPIDER

A native of the Erg Chebbi desert in southeastern Morocco, Cebrennus rechenbergi—also known as the flic-flac spider—has the remarkable ability to cartwheel its way out of danger. When threatened by a predator, it will leap off the ground and do a series of high-energy somersaults to make a quick exit. An alarmed flic-flac spider can tumble forward at a rate of 6.6 feet per second—twice as fast as its maximum walking speed. If pressed, it can even cartwheel uphill. Such talents did not go unappreciated by this spider’s discoverer, bionics expert Ingo Rechenberg, who has built a somersaulting robot based on the flic-flac’s locomotion.

2. BAGHEERA KIPLINGI // A JUMPING SPIDER

Bagheera kiplingi spider
Maximilian Paradiz // Wikimeda Commons // CC BY 2.0

Those who have read Rudyard Kipling’s The Jungle Book may have already figured out that this species was named after the panther who helps raise Mowgli. But its pop culture connection is not Bagheera kiplingi’s only claim to fame. It has a plant-based diet, unlike nearly all other spiders, which subsist predominantly on meat. B. kiplingi feasts on the nutritious nubs of Central American acacias, which the trees produce to feed their colonies of guard ants. The ants protect the trees from predators, but the spiders have learned how to swoop in and steal the nubs without providing any symbiotic benefit. The spiders will also eat nectar and ant larvae, and when times are tough, they’ve been known to practice cannibalism.

3. ARACHNURA HIGGINSI // THE SCORPION-TAILED SPIDER

Arachnura higginsi spider
Peter Woodard // Wikimedia Commons // Public Domain

Two phobias for the price of one! Found only in Australia, the scorpion-tailed spider is so named because adult females have a long, thin appendage on the tip of their abdomens. (Males and juveniles lack this structure.) The females can arch this bendable tail over their backsides, which gives them the appearance of irate scorpions and prompts would-be attackers to keep their distance. But it’s all an act: The tail cannot sting and Arachnura higginsi is mostly harmless to humans.

4. CAEROSTRIS DARWINI // DARWIN’S BARK SPIDER

The male Darwin’s bark spider is eager to please. Really, really eager. The diminutive males exhibit what some scientists have called “a rich sexual repertoire” to their much larger mates. During sex, males nibble on their partners’ genitals or immobilize them with a web of silk before getting busy. Males will also detach their own sexual organs inside their mates to prevent females from mating with others. Researchers muse that this unusual behavior grew out of males’ survival instinct: A female Darwin’s bark spider is liable to eat her partner after mating.

5. GENUS SCYTODES // SPITTING SPIDERS

Scytodes thoracica spider
Fritz Geller-Grimm // Wikimedia Commons // CC BY-SA 3.0

Using webs to catch prey is all well and good, but it almost seems tame compared to what spitting spiders do to their victims. To subdue a target, the killers take aim and fire twin streams of venom-drenched silk out of their fangs. At a top speed of 62 miles per hour, the fibers move in a wide-arced, zig-zag pattern. In addition to being coated with poison, this silk drips with a super-sticky glue. Once victims are enmeshed, the glue-covered fibers will shrink, constricting the unfortunate prey. Eventually, the spitting spider will administer a venomous bite and put the trapped entrée out of its misery.

6. GENUS DOLOMEDES // FISHING SPIDERS

Hydrophobic coats and a knack for exploiting surface tension allow these predators to walk on water. Fishing spiders lurk in North America, Europe, Australia, and New Zealand. To hunt tadpoles, aquatic insects, and even small fish, many species of fishing spiders will splay themselves over the surface of freshwater lakes or streams. Then, using hundreds of ultra-sensitive leg hairs, they monitor aquatic vibrations. When prey swims by, the spider homes in on its precise location and dives for the victim, sometimes as much as 18 centimeters below the water’s surface.

7. CYRTARACHNE INAEQUALIS // A “DISCO SPIDER”

This little fellow—which arachnologist Joseph Koh believes is Cyrtarachne inaequalis, a member of the Cyrtarachne orb-weaver spider genus—made a vivid impression on photographer Nicky Bay, who captured its singular light show on film. The orb-weaver’s abdomen exhibits a pulsating movement that appear to show its internal organs working under a translucent membrane, Bay writes. Scientists have suggested that the spiders’ display attracts prey or scares off predators, but how and why C. inaequalis puts on its tiny disco act remains a mystery.

8. GENUS MYRMARACHNE // ANT-MIMICKING JUMPING SPIDERS

Myrmarachne ant spider

Found in tropical and temperate zones all over the world, Myrmarachne spiders pretend to be ants—which predators view as aggressive and not worth the effort—to stay alive. With their elongated heads and hourglass-shaped thoraxes, the arachnids look a lot like various ant species (their Latin name even means “ant-spider”). To help sell the illusion, they’ll wiggle their front legs like an ant’s writhing antennae. Of course, a good actor knows when to break character. If certain Myrmarachne species come across predators that eat ants, they’ll drop the ruse.

9. SUPERFAMILY PALPIMANOIDEA // ASSASSIN SPIDERS

Assassin spiders are so named because most of them eat smaller, sometimes poisonous spiders. To keep their food from biting back, Palpimanoidea have evolved long, skinny, giraffe-like necks. Their tiny heads sport huge sets of jaws. When an assassin spider finds a meal, those jaws impale the target and swing forward at a 90-degree angle. That keeps victims a safe distance away from any of the assassin spider’s sensitive body parts. Before long, the skewered prey will die on one of the distended jaws. Then the feasting can begin.

10. GENUS SELENOPS // SPIDERS THAT GLIDE

Our planet is home to more than 40,000 different kinds of spiders, and luckily for arachnophobes, none of them can fly. But at least one genus can free-fall like champion parachutists. In a 2015 study, biologists documented this unusual behavior by systematically dropping 59 tree-dwelling spiders of the genus Selenops from “either canopy platforms or tree crowns in Panama and Peru.” Ninety-three percent of these arachnids steered themselves towards nearby trees to land safely on the trunks. The researchers speculate that such gliding descents happen all the time in nature. After all, the spiders predominantly reside in trees—and the ability to parachute from one trunk to the next would be a huge asset.

What's the Difference Between Pigeons and Doves?

iStock
iStock

To the layman, the difference between pigeons and doves has something to with color, maybe. Or location. Or general appeal (doves usually get much better press than pigeons do). But what’s the actual, scientific difference between doves and pigeons?

As it turns out, there isn’t one. Paul Sweet, the collection manager for the department of ornithology at the American Museum of Natural History, says the difference is more linguistic than taxonomic.

“The word dove is a word that came into English from the more Nordic languages, whereas pigeon came into English from French,” Sweet tells Mental Floss.

Both dove and pigeon refer to the 308 species of birds from the Columbidae family, Sweet says. There’s no difference between a pigeon and a dove in scientific nomenclature, but colloquial English tends to categorize them by size. Something called a dove is generally smaller than something called a pigeon, but that’s not always the case. A common pigeon, for example, is called both a rock dove and a rock pigeon.

“People just have their own classification for what makes them different,” Sweet says. “So in the Pacific, for example, the big ones might get called pigeons and the smaller ones might be called doves, but they’re actually more closely related to each other than they are to other things in, say, South America, that are called pigeons and doves.”

The difference boils down to linguistic traditions, so feel free to tell people you’re releasing pigeons at your wedding or that you’re feeding doves in the park. Scientifically speaking, you’ll be correct either way.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

8 Hair-Raising Facts About Black Cats

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iStock

No member of catkind is more maligned than the black cat. At best, they're bemoaned as lackluster photography subjects; at worst, they're seen as harbingers of really bad luck. But there's a lot to love about these furballs, as evidenced by the holidays in their honor—the ASPCA celebrates Black Cat Appreciation Day annually on August 17 and, across the pond, October 27 is National Black Cat Day—and the facts below.

1. IN SOME CULTURES, BLACK CATS ARE GOOD LUCK.

A black kitten stretching
iStock

They may have a less-than-stellar reputation in some areas of the world, but there are plenty of places where black cats aren’t bad luck at all. If you’re a single woman in Japan, owning a black cat is said to increase your number of suitors; if you’re in Germany and one crosses your path from right to left, good things are on the horizon.

2. THEY'RE A SAILOR'S BEST FRIEND.

Not only were cats welcome aboard British vessels to hunt mice, but sailors generally thought a black cat in particular would bring good luck and ensure a safe return home. A few of these kitties have been enshrined in maritime history, like Tiddles, who traveled more than 30,000 miles during his time with the Royal Navy. (His favorite pastime was playing with the capstan’s bell-rope.)

3. THERE IS NO ONE BLACK CAT BREED.

The Cat Fanciers’ Association (CFA) recognizes 22 different breeds that can have solid black coats—including the Norwegian Forest Cat, Japanese Bobtail, and Scottish Fold—but the Bombay breed is what most people picture: a copper-eyed, all-black shorthair. The resemblance to a "black panther" (more on those animals in a bit) is no coincidence. In the 1950s, a woman named Nikki Horner was so enamored with how panthers looked that she bred what we now refer to as the Bombay.

4. BLACK CATS ARE AS EASILY ADOPTED AS CATS OF OTHER COLORS.

Black cat facts.
iStock

It’s common to think that black cats in shelters are the last in line to find their forever homes, but a recent survey from the ASPCA suggests otherwise. Although euthanasia numbers for black cats were some of the highest, their total number of adoptions was the highest of any hue as well. The vet who conducted the study argues that there may just simply be more black cats than other colors.

5. THEIR COATS CAN "RUST."

A black cat’s color all boils down to a genetic quirk. There are three variants of the black fur gene (solid black, brown, and cinnamon), and the hue works in conjunction with the pattern. If a cat has a solid black hue, but also the dominant tabby stripe gene, heavy exposure to the sun can make the eumelanin pigment in its fur break down to reveal its once-invisible stripes (another potential cause: nutritional deficiency). What was once a black cat is now a rusty brown cat.

6. THE GENE THAT CAUSES BLACK FUR MIGHT MAKE THESE FELINES RESISTANT TO DISEASE.

Even though their coloring is what gives them a bad reputation, these felines may be getting the last laugh after all. The mutation that causes a cat’s fur to be black is in the same genetic family as genes known to give humans resistance to diseases like HIV. Some scientists think the color of these cats may have less to do with camouflage and more to do with disease resistance. They’re hoping that as more cat genomes are mapped, we may get a step closer to curing HIV.

7. YOU CAN VISIT A CAT CAFE DEVOTED TO BLACK CATS.

Step through the doors of Nekobiyaka in Himeji, Japan and get ready for your wildest cat lady dreams to come true. Black cats are the stars of this café and visitors are invited to pet (but not pick up) these lithe felines. Each of Nekobiyaka’s identical-looking black cats wears a different colored bandana to resolve any catastrophic mix-ups.

8. THEY'RE DIFFICULT TO PHOTOGRAPH—BUT IT CAN BE DONE.

A black cat is photographed against a blue-gray background
iStock

The modern-day conundrum black cat owners face isn’t bad luck, but bad lighting. In a world filled with people sharing photos of their pets on Instagram, black cats can end up looking like a dark blob in photos. One photographer’s advice? Minimalist backgrounds, so your subject can stand out, and angling them towards natural light sources (but keep them out of bright sunlight!). If you're snapping pics on your iPhone, tap on your cat's face, then use the sun icon to brighten up the photo.

BONUS: BLACK PANTHERS HAVE SPOTS.

Technically, there is no such thing as a black panther—it’s a term used for any big black cat. What we call black panthers are in fact jaguars or leopards and yes, they have spots, too. Their hair shafts produce too much melanin thanks to a mutation in their agouti genes, which are responsible for distributing pigment in an animal’s fur. Look carefully and you can see a panther’s spots as the sunlight hits them in just the right way.

This article originally ran in 2016.

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