Giant vinegaroons, also known as whip scorpions, are fascinating arachnids found in the southwestern United States, parts of Mexico, and southern Florida. These creatures often capture people’s attention due to their intimidating appearance and their striking name, which leads to curiosity about their potential danger to humans.
While their name might suggest a fearsome bite, vinegaroons are not actually venomous, and they do not bite humans. Instead, their primary defense mechanism is a spray containing 83% acetic acid, which can cause irritation if it comes into contact with the skin or eyes. As a result, there is no need to worry about a dangerous or poisonous bite from these unique creatures. In comparison to venomous species like vipers or pit vipers, the threats posed by vinegaroons are significantly less severe.
To help understand the difference between a vinegaroon’s defense and potentially dangerous bites from other creatures, let’s compare their effects:
|Danger to Humans
|83% acetic acid spray; causes irritation
|Puncture marks, swelling, severe pain, nausea, difficulty breathing
|Itchy, reddish-brown bump or blisters; potential disease transmission
So while vinegaroons may look intimidating, their lack of a poisonous bite makes them far less of a threat than other potentially dangerous creatures found in the same regions.
The giant vinegaroon, scientifically known as Mastigoproctus giganteus, is a large arachnid found in North America, Mexico, Florida, Arizona, Texas, and New Mexico. They belong to the arthropod family Uropygi, with over 120 known species worldwide.
Classification and Characteristics
Vinegaroons are nocturnal creatures with poor vision. They rely on sensing vibrations to locate their prey. Some remarkable characteristics of vinegaroons include:
- Non-poisonous, but capable of pinching
- Can spray a mist containing 83% acetic acid
- Special teeth on the inside of their front appendages, used for crushing prey
These arachnids are often mistaken for scorpions or spiders due to their physical similarities. However, they are distinct from both, belonging to their own unique group of arthropods.
|Yes (some species)
|Yes (some species)
|Acetic Acid Spray
Habitat and Distribution
Vinegaroons inhabit a diverse range of environments, including:
- Desert areas
- Pine forests
While they are more common in desert regions, their distribution spans from North America and Mexico to Southeast Asia. Vinegaroons adapt well to various ecosystems, making them a widespread and fascinating species to study.
Vinegaroon Behavior and Diet
Vinegaroons are nocturnal arachnids with poor eyesight. They rely on sensing vibrations to locate their prey. These creatures are mostly found in desert areas but can also be spotted in other habitats like grasslands, pine forests, and mountains.
Their diet primarily consists of other insects and arachnids, such as:
Occasionally, they do prey on small vertebrates, like lizards. While hunting, vinegaroons utilize their whip-like tail to capture their prey.
Vinegaroons have a limited number of predators due to their intimidating appearance and acidic spray. However, they still fall prey to some natural predators, including:
- Larger arachnids
Comparison of Vinegaroon Prey and Predators
These arachnids often seek shelter under leaf litter, rocks, and logs, which provide camouflage and protection against their predators. Overall, vinegaroons possess fascinating hunting strategies and exhibit interesting dietary patterns that largely involve invertebrates, with a few vertebrates occasionally. Their nocturnal nature and elusive habitats limit their interactions with other species and help them avoid predation while hunting for their prey.
Vinegaroon’s Defense Mechanisms
Vinegaroons, also known as whip scorpions, are famous for their acidic spray. They possess pygidial gland secretions containing 83% acetic acid. This strong acid is similar in concentration to vinegar and serves as their primary defense mechanism. When threatened, they can release a spray that can cause irritation or even pain if it comes into contact with an enemy’s skin or eyes.
Scent Glands and Caprylic Acid
In addition to their acidic spray, vinegaroons have scent glands at the base of their abdomen. These glands produce a mist rich in caprylic acid. Caprylic acid is a weaker acid than acetic acid, yet it can still be an effective deterrent against potential predators.
Pros of Using Acidic Spray and Caprylic Acid:
- Effective in warding off predators
- Quick response to threats
Cons of Using Acidic Spray and Caprylic Acid:
- Can cause unintended harm to surrounding organisms
- Acetic acid can produce a strong and unpleasant odor
Not only do they have the ability to spray acid, but vinegaroons also utilize pinching mouthparts for self-defense. Their special teeth on the insides of their front appendages can crush prey or even deter potential predators. Although their bite is not poisonous and may not cause severe pain, it can be an uncomfortable experience for anything that comes too close.
Comparison Table: Defense Mechanisms
|Moderate to High
|Low to Moderate
|Low to Moderate
In summary, giant vinegaroons possess a variety of defense mechanisms to protect themselves in their scrub, grassland, and mountain habitats. With their unique combination of acidic spray, scent glands, and pinching mouthparts, these whip scorpions ensure their survival in the wild against potential predators.
The Vinegaroon Bite
Is It Poisonous?
Giant vinegaroons, or Mastigoproctus giganteus, are not considered poisonous despite being a type of arachnid. They lack the venom-filled stinger found in scorpions and the venomous bite of some spiders1. As a nocturnal species, they rely on sensing vibrations to locate prey2.
Features of the vinegaroon:
Symptoms and Effects on Humans
When threatened, vinegaroons use their tails to release a mist from scent glands at the base of the tail2. This defense mechanism is not dangerous to humans, but the mist does have a strong vinegar-like smell.
Vinegaroon encounters with humans can result in a pinch, which can be painful but is not venomous1. A pinch might cause some initial discomfort, but it doesn’t pose any lasting health threats.
Characteristics of a vinegaroon bite:
- Painful pinch
- Not venomous
- Strong vinegar smell from mist release
|Bite / Sting
|Danger to humans
|Mist from scent glands
In conclusion, the giant vinegaroon’s bite is not poisonous to humans, and the pain experienced from a pinch is temporary. Their unique scent gland defense mechanism serves as an effective deterrent to would-be threats but presents no lasting danger to humans.
Interactions and Encounters with Humans
How to Avoid a Vinegaroon
Vinegaroons are dark brown arachnids typically found in soil or under logs. They can grow to a considerable size, with some genera reaching a lifespan of several years. To reduce the likelihood of encountering vinegaroon:
- Be cautious in areas with loose, moist soil, especially near logs or rocks.
- Keep an eye out for them during their activity period, which is usually around dusk.
- Wear gloves and closed-toe shoes when working outdoors, especially in areas where they are known to reside.
- Keep your living spaces clean and free of clutter to discourage them from taking up residence indoors.
First Aid Measures
Vinegaroons are not known for biting humans. Instead, they release a concentrated acetic acid (similar to vinegar) spray from their pygidial glands when threatened. Although the spray can be irritating and painful, it’s not seriously harmful. However, if it contacts the eyes, it can cause temporary discomfort and vision issues.
If you are sprayed by a vinegaroon, here are some first aid measures to consider:
- Rinse the affected area with copious amounts of water for at least 5-10 minutes.
- If eyes are involved, hold the eyelid open while flushing to ensure the irritant is properly removed.
- Seek medical advice if symptoms persist or worsen.
In general, vinegaroons should not pose a significant threat to humans when given space and respect. Following these basic measures can help minimize your risk of an unpleasant encounter.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Giant Vinegaroon
Scorpion like bug in New Mexico
Attached is a photo of a rather large and intimidating “bug”. It has claws like a scorpion, but not the curved tail with the stinger. Instead it has that long thin wiry tail. The tail actually looks like a long piece of wire of stiff hair. Can you tell us what it is? Is it poisonous or harmful to humans? Does it eat other insects? Thanks.
Monte and Mary Kern
Hi Monte and Mary,
This is a harmless Whipscorpion, Mastigoproctus giganteus, also called a Giant Vinegaroon or Grampus. Legend has it that the bite of a Vinegaroon will cause the person to taste vinegar for weeks. Though this is untrue, BugGuide notes that “Although its tail in unable to sting, this creature can spray an acidic mist from a scent gland at the base of the tail when disturbed. The spray is 85% concentrated acetic acid/vinegar, hence the common name “Vinegaroon.” The heavy pinching mouthparts (modified pedipalps) can also inflict a painful bite. Although very unlikely to attack humans, it can certainly defend itself if provoked.” The Vinegaroon is a nocturnal predator with poor eyesight. It feeds on insects, other arthropods, and also, probably, small vertebrates like lizards.
Letter 2 – Giant Vinegaroon
Scorpion or not?
June 24, 2010
This bug was found at our campsite in the Davis Mountain State Park near Ft Davis, Texas. Pinchers and hard body suggest scorpion but the stinger and fore legs do not match any species I have searched, the bug was very aggressive as well. What is it?
West Texas Camper
Davis Mountain State Park. Ft Davis,Tx.
Hi West Texas Camper,
This is a Giant Vinegaroon, Mastigoproctus giganteus, one of the Whipscorpions which are not true scorpions. Unlike their stinging relatives, Giant Vinegaroons do not sting and have no venom. They do secrete a concentrated acetic acid that smells like vinegar, hence the common name. According to BugGuide: “The vinegaroon is nocturnal and has poor vision. The whiplike tail is used as a sensory organ, as is the first pair of legs, which is not used for walking. Although its tail in unable to sting, this creature can spray an acidic mist from a scent gland at the base of the tail when disturbed. The spray is 85% concentrated acetic acid/vinegar, hence the common name ‘Vinegaroon.’ The heavy pinching mouthparts (modified pedipalps) can also inflict a painful bite. Although very unlikely to attack humans, it can certainly defend itself if provoked.” We have also seen the name Grampus used in literature regarding the Giant Vinegaroon.
Thank you Daniel. Your response is greatly appreciated. The Giant Vinegroon was quite a site for my 11 year old daughter, she was horrified when she saw it while roasting marshmallows around our camp fire. We did notice a vinegar smell in the air and just couldn’t place its origin. Thanks again!
Letter 3 – Giant Vinegaroon
Location: cr 204 in Mitchell Co Texas
September 21, 2011 8:02 pm
Could you help us to ID this bug. We have never seen it before.
This harmless Whipscorpion is sometimes called a Giant Vinegaroon because it can spray a mild acetic acid that smells like vinegar. Unlike Scorpions, Whipscorpions do not have venom.
Letter 4 – Giant Vinegarone
What bug do I have?
I found this bug outside of my house on my porch right after a rain storm on 10/4/07. I live in New Mexico at about 5500ft on the plains west of the Sandia Mountains in central New Mexico. The body is like a beetle, but it has pinchers like a scorpion. The tail is about 2 inches long, and appears to act like an antenna of sorts but does not appear to be a stinger. It gives off an awful and irritant smell that hurts the eyes and throat. This thing is freaky and looks like a cross breed of a scorpion and a beetle. The picture does not illustrate its size. It is about 3 inches long. Please let us know, if you are familiar with what it is.
This Whipscorpion is commonly called a Vinegarone, or Grampus in the South. It is a harmless relative of scorpions and it gets the name Vinegarone because of the vinegar scented acid they release from a gland near the tail. They are shy nocturnal hunters that are seldom encountered.
Letter 5 – Giant Vinegaroon
What’s this bug!
Hi I live in New Mexico, and while remodeling an old building my grandfather found two weird big bugs. He decided to hand them over to me, I’ve had them for over a year and I am still curious in finding out what they are. Here are some pictures, I hope you can help me out. To describe them more, they are about the size of standard size tweezers and are dark brown in color, they have claws much like a scorpion but a tail like a cocroach, long and slender. Please help me out.
Your critters are Giant Vinegarones, also known as Grampus, Mastigoproctus giganteus. They are Whip Scorpions in the Family Thelyphonidae. They are found in the South and Southwest and are rarely seen since they hide during the day. Despite their fearsome appearance, they are harmless.
Letter 6 – Giant Vinegaroon
hurry and look please
Location: Southwest Central NM
September 30, 2010 11:54 pm
Seriously this thing freaks me out and its in my garage
Despite its fearsome appearance, the Giant Vinegaroon, Mastigoproctus giganteus, is perfectly harmless. Also known as a Whipscorpion, it is a shy, nocturnal predator that has no venom, unlike its distant relatives the true Scorpions. Like many creatures, it might bite if carelessly handled, but we must stress that it does not have venom. This is what BugGuide indicates: “The vinegaroon is nocturnal and has poor vision. The whiplike tail is used as a sensory organ, as is the first pair of legs, which is not used for walking. Although its tail in unable to sting, this creature can spray an acidic mist from a scent gland at the base of the tail when disturbed. The spray is 85% concentrated acetic acid/vinegar, hence the common name ‘Vinegaroon.’ The heavy pinching mouthparts (modified pedipalps) can also inflict a painful bite. Although very unlikely to attack humans, it can certainly defend itself if provoked.”
Letter 7 – Giant Vinegaroon
is this a tailless whip scorpion
Location: Sierra Vista AZ
August 31, 2011 5:25 pm
Found this in my garage. Is it a tailless whip scorpion?
This Giant Vinegaroon, Mastigoproctus giganteus, is classified in the Arachnid order Uropygi while Tailless Whipscorpions are classified in the order Amblypygi. The Giant Vinegaroon is considered a Whipscorpion, but it is not tailless.
Letter 8 – Giant Vinegaroon
Location: central fla
October 28, 2011 9:47 am
bug with crab like claws spider face,found in merritt island fl.
Though this Giant Vinegaroon is an Arachnid that is distantly related to venomous creatures like spiders and scorpions, the Vinegaroon does not pose a threat to humans as it has no venom. It is capable of releasing a mild acetic acid that smells like vinegar, hence the common name. The Giant Vinegaroon is a Tailless Whipscorpion that is also sometimes called a Grampus.
Letter 9 – Giant Vinegaroon
Subject: Indentification please?
Geographic location of the bug: South of of Alamogordo, NM
Time: 09:16 AM EDT
Your letter to the bugman: Not sure this is an insect. The front appendages do seem to be pincers. The overall length including the “tail” is over 8″! Seen July 17, 2018.
How you want your letter signed: Dave and Teri
Dear Dave and Teri,
This is a Whipscorpion, Mastigoproctus giganteus, commonly called a Giant Vinegaroon or Grampus. Though related to Scorpions, they are not considered dangerous as they lack venom, but they can secrete a weak acetic acid that smells like vinegar. Giant Vinegaroons are shy, nocturnal predators with powerful mandibles, so they are capable of biting. At the risk of being repetitive, according to BugGuide: “The vinegaroon is nocturnal and has poor vision. The whiplike tail is used as a sensory organ, as is the first pair of legs, which is not used for walking. Although its tail in unable to sting, this creature can spray an acidic mist from a scent gland at the base of the tail when disturbed. The spray is 85% concentrated acetic acid/vinegar, hence the common name ‘Vinegaroon.’ The heavy pinching mouthparts (modified pedipalps) can also inflict a painful bite. Although very unlikely to attack humans, it can certainly defend itself if provoked.”