- Common Name:
- Vinegaroon, tailed whip scorpion
- Scientific Name:
- Average Life Span In The Wild:
- Up to 9 years
- Up to 2.4 inches long, excluding the tail
- Up to 12.4 grams
What is a vinegaroon?
The vinegaroon is a small, black, desert predator that looks like a bit like an alien. In truth, these fierce-looking animals, which weigh less than a AAA battery, are no threat to humans.
Sometimes called tailed whip scorpions, vinegaroons can also be distinguished from two other groups of arachnids with similar-sounding names: shorttailed whip scorpions from the order Schizomida, which have much smaller flagellums, or tails, and tailless whip scorpions, which belong to the order Amblypygi.
Vinegaroons are not venomous. However, when threatened, the vinegaroon can spray a sour-smelling acetic acid from glands on its abdomen. This vinegar-like secretion is also where the animals get their common name from. The spray is most effective when it comes into contact with a predator’s eyes, where it can cause temporary blindness, says entomologist Justin O. Schmidt, but it can also sometimes cause irritation to human skin.
The acid is an incredibly potent predator deterrent, says Schmidt, who spent a decade studying vinegaroons in their natural habitat with his wife, Li Schmidt. In fact, the husband-and-wife duo learned that very few animals will even attempt to prey upon vinegaroons, and what’s more, those that do kill and eat one rarely go back for seconds.
“Imagine you’re a small rodent, toad, frog, or lizard,” says Justin, who is also the author of a book called The Sting of the Wild. “You get hit with this corrosive, vinegary spray, and it’s going to catch your attention.”
Habitat and diet
Native to deserts, scrublands, dry grasslands, pine forests, and barrier islands of the southern United States and Mexico, vinegaroons are very good at remaining hidden from human view. Part of this is because the animals are almost entirely nocturnal.
Even after dark, the animals are difficult to find, because they are sit-and-wait predators. Hiding within crevices, the predators wait for dinner to wander nearby, sensing the vibrations an animal makes on the sand or soil with sensory hairs. Then, when the target is within striking distance, the vinegaroon will lurch forward and grab its victim with large pincers, or pedipalps.
While it’s been commonly thought that vinegaroons like to feast on one another, Justin Schmidt found the opposite to be true in a study published in The Journal of Arachnology in 2022. In fact, his experiments revealed that cannibalism is exceedingly rare, and usually only happens when adults run into much smaller and younger vinegaroons.
Instead, a normal vinegaroon diet consists of beetles, caterpillars, ants, flies, and crickets— “pretty much anything that they can overpower,” he says.
Lots of people mistakenly think of insects, arachnids, and other “lower animals” as being simple. But vinegaroon reproduction is a complex affair.
First, a male and female vinegaroon will use their pedipalps to grapple. While Justin Schmidt isn’t sure what qualities they’re assessing in each other—perhaps size, speed, or age—he’s seen both sexes walk away from pairings that didn’t suit them, for whatever reason.
If both vinegaroons are satisfied, they move on to a dancing stage, which can last more than an hour. This is where the male holds the female’s sensory antennae in his mouth and the duo sways back and forth.
Next, while he maintains a grip on the female’s delicate sensors, the male generates a spermatophore packet. This laborious process can take three to four hours, after which he guides the female onto the packet and assists as she places it into her reproductive opening.
“The whole process can take more than 13 hours to complete,” says Justin.
Afterward, the female will lay a clutch of up to 52 eggs, which she then guards against predators. After they hatch, she will also share any prey she catches with the brood.
“I've got pictures of mama holding this piece of caterpillar, and dozens of babies are just swarming all over on top of her, chewing on the same thing that she is,” says Justin. “That’s obviously maternal care—feeding them and taking care of them—and again, this is not a sign of a primitive animal behavior.”
Did you know?
— Oakland Zoo
The giant vinegaroon can spray up to 19 times before its acid glands are depleted.
— Animal Diversity Web
Vinegaroon courtship can last up to 13 hours.
— The Journal of Arachnology
While they might look frightening, vinegaroons pose no threat to humans. In fact, some people keep them as pets!
— The Arizona Republic