A few days ago I was walking to our garden, and I spotted a really cool, inch-long insect scuttling around on the ground at my feet. I recognized it as a velvet ant, a creature that fascinates me but which I rarely have a chance to see. I tried for several minutes to get a decent photo with my phone, but the darn thing was on a mission. It wouldn't stop scurrying for even a split second, so here's my best shot:
Here in Missouri, velvet ants are often called cow killers. This menacing name comes from their reputation for having an extremely painful sting. You see, these creatures are not actually ants at all—they are wasps.
What the heck is a Velvet Ant?
Amazingly, there are over 7,000 species of velvet ants worldwide! They are in a family called Mutillidae. As you can probably guess, they get their common name (velvet ant) from the velvety coat of fur on their bodies, which is often bright orange and black.
Here are a few of the different species:
Amazing Facts about Velvet Ants
First, let's make sure we know exactly what these things are. As I said above, velvet ants are actually wasps. They exhibit what is called sexual dimorphism—meaning the males and females are very different in appearance. The males have wings and can fly, while the females are without wings and spend all their time on the ground. The wingless females can sting, but the winged males cannot.
Velvet ants are solitary wasps. They live alone instead of in colonies that have queens, workers, and drones. The adult males fly around at night, feeding on flower nectar. The wingless females also feed on nectar, but they move around on the ground, often during daylight hours.
Here is what a winged male looks like:
Okay, we really need to talk about this wasp's amazing ability to defend itself. It is perhaps the best-defended type of wasp. First, its stinger packs a mean punch. In fact, legend has it that the sting is powerful enough to kill a cow. Hence the name cow killer. Don't worry, this is nothing more than a legend. These wasps are not dangerous to cows or to humans (unless you are highly allergic to wasp and bee stings in general).
But the velvet ant's sting is painful! How painful? Well, first let's distinguish between pain and toxicity. Pain is how much the sting hurts, toxicity is how dangerous or fatal the sting is. Surprisingly, tests have shown that velvet ant venom (which still has an unknown composition) is no more toxic than the venom of honeybees.
It's also important to think about the velvet ant's solitary lifestyle. They live alone, so they do not have companions to help them fight off predators. It's more important for a velvet ant to administer immediate pain to a predator, so that it can make a quick escape. It's the "shock and awe" approach. When a predator grabs a velvet ant, the pain comes so fast that it will usually release the wasp before killing it.
How painful is it? In one comparative study, velvet ant pain outscored the pain from 58 other stinging insects. The only bugs rated as more painful were the bullet ant, the warrior wasp, and the tarantula hawk (a type of wasp). Even those names sound nasty, don't they?
Oh... and that was one study I am glad I did not volunteer for.
I suppose the pain is made worse by the fact that velvet ants have stingers that can be half as long as their entire body! See the stinger in the image below.
Not only do velvet ants have a nasty sting, they also make a warning sound by contracting their abdomen. This sound warns predators that the velvet ant is ready to attack (kind of like a rattlesnake's rattling). In studies, whenever a shrew would come within a meter of a velvet ant, the velvet ant would start making this sound, and the sound would become more frequent as the shrew got closer. In the study, the shrews would never attack the velvet ants.
Check out this video of a velvet ant's alarm sound and its stinger.
But wait! The painful sting and the threatening noise are not the velvet ant's only defenses. The bright orange and black colors are actually a form of aposematic coloration. This means they have evolved a specific combination of colors to scare off predators (kind of like the coral snake). Many predators have learned the hard way that touching a velvet ant involves pain, and they learn to avoid insects that have this color pattern.
Not only that, but velvet ants have extremely strong, hard exoskeletons. Crushing a velvet ant requires 11 times more pressure than crushing a honeybee! Yep... this has actually been measured with a device called a force transducer.
And there is one more defense. When threatened, velvet ants also squirt out an alarm chemical from their mandibular gland. It is thought that this chemical further warns the attacker that they are about get the crap stung out of them if they don't back off.
So... a painful sting, aposematic coloration, a really hard exoskeleton, a warning sound, and a warning chemical. Velvet ants are well-defended wasps!
To give you an idea of how invincible velvet ants are, in a large 2018 study, numerous species of velvet ants were placed with a variety of different predators, including amphibians, reptiles, birds, and small mammals. The wasps were attacked by moles, shrews, lizards, birds, frogs, toads, and many more predators. Only one animal, a single American toad, was able to kill and eat a velvet ant. All the others failed. Two shrews were able to wound a velvet ant, but only after several failed attempts.
The velvet ant is one tough cookie.
One last photo. Below is a species of velvet ant found in Chile. It's called the panda ant.
So, Velvet Ants deserve a place in the G.A.H.O.F.
(Gangbusters Animal Hall of Fame).
FUN FACT: The word gangbusters originated in about 1940. It comes from the popular U.S. radio crime-fighting drama called "Gang Busters," which ran from 1937-1957. The show always started with a dramatic opening involving sirens, screams, pistol shots, and jarring music. The show often involved law enforcement officials busting up organized crime gangs. Eventually, the word started being used widely to mean "outstandingly excellent or successful." Example: The new Marvel movie went gangbusters. The word can also mean "with great speed, intensity, vigor, impact, or success." Example: The software market was growing like gangbusters.
So, especially when it comes to velvet ants, gangbusters is another way to say awesome!
Immortal Jellyfish - Animal Rescue Professionals
Young chimp with stick - National Geographic
Velvet ant species comparison - Joe Wilson/Joe Wilson et al./Current Biology 2015 via The Guardian
Winged male - Johnny N. Dell, via Tallahassee Democrat
Velvet ant stinger - Joseph S. Wilson, USU, via Utah State University Today
Panda ant - Chris Lukhaup - Flickr
Everyone needs a creative outlet. That's why I write.