Not a fan? Consider vacationing in Antarctica—the only continent with no resident scorpions. Love them or hate them, there’s no denying that the creepy crawlies are an amazingly successful bunch, with over 1500 known species lurking about. Here’s a quick guide to these wonderful arachnids.
1. BABIES RIDE ON THEIR MOTHER’S BACK FOR PROTECTION.
While spiders lay eggs, pregnant scorpions take a different approach. In a process called ovoviviparity, babies hatch out of eggs that gestate within their mother’s body and then emerge from her as fully developed infants. Once outside, the tiny newborns are more or less helpless. So, for some much-needed security, they take up residence atop mother’s back. Here the babies remain until their first molt takes place—usually around one week later.
Scorpions make interesting parents. On the one hand, mothers of several species will crush up small insects and feed bite-sized chunks to their brood. However, should food get scarce, a female often resorts to eating her own progeny.
2. MASSES OF SCORPIONS WILL SOMETIMES SPEND THE WINTER TOGETHER.
During most months, scorpions tend to be solitary animals. But between November and March, a few species—like the dreaded North American bark scorpion—are prone to hunker down under some type of shelter (manmade or otherwise). There, upwards of 40 individuals can hibernate side by side. Naturally, discovering such a slumber party is every arachnophobe’s worst nightmare.
Believe it or not, many scorpions literally freeze while hibernating. Upon springtime’s return, they thaw out and track down a meal.
3. SO-CALLED “WHIP SCORPIONS” AREN’T TRUE SCORPIONS AT ALL.
If you live in a tropical or subtropical part of Africa, Asia, or the Americas, you may’ve had some personal experience with whip scorpions (also known as “vinegaroons” and “uropygids”). Unlike real scorpions, which belong to a different arachnid order, these oddball invertebrates lack stingers and venom glands. Instead, a long, whip-like appendage protrudes from the hind end. Near its base lie two openings which can fire off twin streaks of a highly acidic, vinegar-like spray. Should this stuff land in an attacker’s eye, temporary blindness might follow.
4. THEY HAVE INCREDIBLY SLOW METABOLISMS.
Scorpions take leisure to a whole new level. Many spend 92 to 97 percent of their lives sitting motionless in burrows. Because they expend little energy, they can get by on very little nutrients. Some scorpions have been known to go over a year between meals.
5. THE SMALLEST KNOWN SCORPION IS LESS THAN A HALF-INCH LONG.
Discovered in 2014, Microtityus minimus (common name pending) is indigenous to the Dominican Republic, where it occupies southern foothills. At 0.4 inches from end to end, it’d look like a real pip-squeak beside either of the two biggest scorpions on Earth: India’s Heterometrus swammerdami and the African Pandinus imperator (aka the “emperor scorpion”), which grow from 5.9 to nearly 8 inches long.
6. ONE MOUSE IS AMAZINGLY RESISTANT TO PAINFUL SCORPION STINGS.
Human victims who’ve had a run-in with the business end of an Arizona bark scorpion (Centruroides sculpturatus) feel an intense burning, prickly sensation. For grasshopper mice, the whole experience is a lot less dramatic.
Unlike the typical house mouse (a distant relative), the grasshopper mouse has a mutation that neutralizes the venom of the bark scorpion, which it eats. In order to feel pain, two separate steps are required: first, something must initiate the signal which then has to reach the brain. But something else happens when a grasshopper mouse gets stung by one of these scorpions—after the venom is injected, the ensuing pain signal never gets sent to the brain.
This trick probably evolved to keep the mammals from starving. As neurobiologist Ashlee Rowe explains, dietary options are extremely limited out in the Arizona desert, where the stinging scorpions “represent a really valuable food resource” for the mice.
7. COURTSHIP DANCES CAN GET RATHER ROUGH.
Come mating season, males of several scorpion species seize their partner by the pedipalps (pincers). Should she resist his advances, a male might give the female a “kiss,” pressing his jaws against hers. That’s when things get unpredictable. Sometimes, the scorpions proceed to circle each other—claw in claw—for hours on end. And, sometimes, one or both parties repeatedly sting the other.
If all goes well for the male, he releases a packet of sperm, which sticks onto the ground beneath him. Then, he physically drags his mate over the packet, hoping that she grabs it and stuffs it into her genital opening. In the aftermath, the female either abandons her partner, or—worst-case scenario—eats him.
8. THEY GLOW UNDER UV LIGHTS.
Looking for scorpions after dusk? Bring a portable black light. Under an ultraviolet beam, the invertebrates glow like novelty children’s toys, emitting a strange bluish green hue. Nobody’s quite sure why they do this, but experts have their theories.
In 2010, arachnologist Carl Kloock and his colleagues at California State University exposed a series of scorpions to ultraviolet beams. Beneath higher UV levels, the test animals stayed relatively inert, becoming more active only when the lights were turned down.
Moonlight could explain his findings. By and large, scorpions are nocturnal. Throughout the day, the Sun emits far more ultraviolet waves than those reflected by the Moon at night. “They may be using UV as a way to determine whether or not to come to the surface to look for prey, based on the light levels,” Kloock says.
This still doesn’t explain why scorpions become fluorescent, though. For the record, Kloock thinks the glowing phenomena is probably “part of the mechanism by which the scorpions respond to moonlight.”
9. A SCORPION’S EXOSKELETON MIGHT ACT LIKE ONE GIANT EYEBALL.
Even with their stingers, scorpions are vulnerable in the open. When not out hunting, the animals instinctively seek shelter—which isn’t easy to locate in pitch-black darkness. Nevertheless, they’re quite good at tracking down hiding spots at all hours of night.
University of Oklahoma biologist Douglas Gaffin thinks that a special optic talent helps scorpions navigate the gloom. Their exoskeleton, he believes, gathers “stray UV light” from the Moon and stars. Theoretically, this converts the creature’s outer casing into a “whole-body light detector” that sends information directly to the brain.
If true, this would mean that a scorpion can use its entire exoskeleton as an extra-large eye. To test his bold hypothesis, Gaffin exposed more than 100 scorpions to UV light and covered the eyeballs of some with foil. The blindfolded arachnids moved just as normally as the control specimens did. These results suggest that Gaffin’s hunch may well have some merit.
10. FEWER THAN 25 SPECIES CAN KILL PEOPLE.
Scorpion attacks can cause anything from mild discomfort to muscular twitching to irregular heartbeats. Yet, only around two dozen species are capable of taking human life. Among these outliers, the “southern man-killer” (Androctonus australis) is particularly infamous in north Africa, where it’s responsible for 95 percent of scorpion-related fatalities.
Also, note that these arachnids are especially dangerous to children. The Brazilian yellow scorpion (Tityus serrulatus), for instance, reportedly kills 3000 people a year, many of them young.