Dr. M Grampus

One of Bailey's friends.

Kelly’s Field Notes

Common Name: Whip scorpion, Vinegaroon (meaning great vinegar or very vinegary), Grampus

Order: Uropygi ("tail rump" in Ancient Greek)

Family: Thelyphonidae

Species of Note Near You (There are around 120+ species of whip scorpion! We have a very poor understanding of their current taxonomy.):


Whip scorpions or vinegaroons are found in the southwestern U.S. and Florida, Mexico, southeast Asia, Africa, and South America - deserts, dry mountains, pine forests, tropics and sub-tropics. They are not found in Europe or Australia! Whip scorpions are burrowers and prefer to hang out underneath the soil, rotting wood, leaf litter or in other covered spaces during the day. At night they roam looking for food.

Whip scorpions are between 2.5-8.5 cm (1.0-3.3 in) in length. They resemble scorpions, with large pinchers but they are lacking that classic scorpion tail. Instead, they have a whip-like flagellum used to pick up chemical cues and vibrations. Underneath the tail they can excrete a mix of water and acids, from a bulbous gland, to deter predators. The liquid smells like vinegar, hence the common name vinegaroon (no venom glands). They are generally brown or black in color. Whip scorpions have a pair of eyes at the front of their cephalothorax, with up to five pairs going up the back of the cephalothorax (similar to actual scorpions, Order Scorpiones). The arrangement of the eyes is species specific. While arachnids, they walk on six legs, using their front two legs as sensory organs (think long antennae but legs). The first two legs are called “annteniforms.”These long sensory organs are necessary as whip scorpions have poor eyesight. Their pedipalps have been converted into pincers. 

Whip scorpion sometimes refers to Order Schizomida, the short-tailed whip scorpions, which is not what we are discussing here (but maybe a future episode!). Whip scorpions of both groups are related to whip spiders under supra-order, clade Pedipalpi, along with tailless scorpions and spiders. Like many arthropods, there were examples of this group dating back millions of years. Examples of whip scorpions have been found as far back as 350 million years ago, during the The Carboniferous Period. They do not glow under UV light like scorpions.

Life Cycle: 

Whip scorpions can live for about 7 to 9 years total, with 4 of those years as adults. They can live well past 10 years in captivity.  Mating takes place in the Fall, with courtship lasting on average 13 hours. Whip scorpion courtship has four stages: Chase and Grapple, Dancing,

Generating, and Pressing. 

Chase and Grapple - males will grab females in their pedipalps and a wrestling match ensues. At one point, one adult will sometimes lift the other off of the ground. The male will try to grab the female’s antenniforms. If she is receptive she will let him, if not she will struggle and keep them out of reach. If she is immediately into it, she will wiggle the annteniforms in front of his chelicerae. If she is not, this struggle can take several hours before they part ways.

Dancing - the pair will now face each other, with the male touching the female with his annteniforms. He will lead, while they move back and forth in a coordinated “dance.” During this time they look for shelter to continue the courtship.

Generating - during this stage the male creates a spermatophore (sperm package) which can take some time and lots of energy to do. This process can take over 6.5 hours. He doesn’t move during this stage and the female waits beside him. When the packet is ready, he positions the female with her gonopore opening (genital opening) over the packet. He then positions himself over her.

Pressing - the male strokes the sperm packet which likely helps to move the sperm into her gonopore. This can go on for up to 7 hours.

The female will carry 30-50+ fertilized eggs for several months. The female will then retire to her burrow, lay the eggs in a fluid filled sac underneath her abdomen, and then she will wait there for about 2 more months for the eggs to hatch. She does not eat, instead focusing on keeping the egg sac off of the ground. Whip scorpion offspring are tiny and white when they hatch. A mother’s job never ends, as once they hatch the young hop up on her back and she carries them around for another month. The young will stay with their mother until after their first molt. Then, looking like miniatures of adults, the young head off on their own and the mother dies. The time it takes to molt is not set in stone, like in other arthropods. Whip scorpions can delay their molt until they have eaten a sufficient amount of food.

Whip scorpions prey upon other smaller invertebrates and small lizards. They are nocturnal and prefer to bring prey back to their burrows to eat.

Super Powers:

Whipscorpions in Culture:

Care Advice from Friend of the Show, Bailey

Vinegaroons make for excellent pets. They're harmless and easy to care for, which makes them appealing to many. This care information is mostly for Mastigoproctus species native to the US-- the giant vinegaroons. Care may differ for other species, but the basics will remain the same. 

They do best with very deep substrate. Being rather fossorial in the wild, they're happiest when allowed to excavate and perfect their burrows. A substrate that holds moisture and holds burrows is ideal. My preferred substrate is plain topsoil mixed with coco fiber, some sand, and excavator clay. Also provide some cover like cork bark, plastic plants, etc. You'll find that they're very particular about their burrows. Sometimes, if given small objects, they'll move them around the enclosure. They're avid interior designers! Be sure that any water dish you provide is shallow enough to easily climb out of. 

They're primarily insectivorous, and do well on a diet of common feeder insects like crickets, roaches, superworms, mealworms, isopods, etc. They're not picky, and eat just about anything they can get their claws on in the wild, by hunting or scavenging.

Mastigoproctus are only active a handful of months out of the year in the wild. While they're typically more active in captivity, they will still naturally hide in their burrows for months on end. So if your vinegaroon has been MIA for a while-- don't panic. They're likely completely fine, and immature individuals may be molting, and mature females could be producing an eggsac.

Unfortunately, the vast majority of vinegaroons in captivity are wild caught. They're collected in large numbers during their active season and sold in the pet trade. It is highly recommended for this reason to find someone breeding them rather than buying wild caught individuals. This helps protect their wild populations, and encourages more captive breeding! As a bonus, you'd be able to enjoy the full lifespan of a healthy vinegaroon raised from a baby, rather than gambling on a potentially old or sick individual.

More advice here!


Barrales-Alcalá, Diego, Oscar F. Francke, and Lorenzo Prendini. "Systematic revision of the giant vinegaroons of the Mastigoproctus giganteus complex (Thelyphonida: Thelyphonidae) of North America." Bulletin of the American Museum of Natural History 2018.418 (2018): 1-62.

Garica, Ursula Pamela. “Three New Species of Giant, Acid-Spitting Creatures Discovered in Mexico.” Yourweather.co.uk | Meteored, 22 Oct. 2023, www.yourweather.co.uk/news/trending/three-new-species-giant-acid-spitting-creatures-discovered-mexico-wildlife.html. Accessed 16 Feb. 2024.

“Giant Whip Scorpion - Mastigoproctus Giganteus Giganteus (Lucas, 1835).” Entnemdept.ufl.edu, entnemdept.ufl.edu/creatures/misc/misc/giant_whip_scorpion.htm.

‌Huff, Jeremy C., and Lorenzo Prendini. "On the African whip scorpion, Etienneus africanus (Hentschel, 1899)(Thelyphonida: Thelyphonidae), with a redescription based on new material from Guinea-Bissau and Senegal." American Museum Novitates 2009.3658 (2009): 1-16.

Schmidt, Justin O., Li S. Schmidt, and Jillian Cowles. "Reproduction and life history of the vinegaroon Mastigoproctus tohono." The Journal of Arachnology 49.3 (2021): 371-379.

“The Giant North American Vinegaroon? It’s Actually Seven Different Species | AMNH.” American Museum of Natural History, 2018, www.amnh.org/explore/news-blogs/research-posts/the-giant-north-american-vinegaroon-it-s-actually-seven-different-species. Accessed 16 Feb. 2024.

‌“Uropygi.” Wikipedia, 28 Nov. 2023, en.wikipedia.org/wiki/Uropygi. Accessed 16 Feb. 2024.

“Vinegaroon, Facts and Information.” Animals, 16 Dec. 2022, www.nationalgeographic.com/animals/facts/vinegaroon. Accessed 16 Feb. 2024.