What yellowjacket stings reveal about how scientists measure pain

If you’ve ever been stung by a yellowjacket you belong to an unexclusive club. The black-and-yellow insects are common throughout the United States and infamous for having an aggressive attitude toward humans. 

But are yellowjacket stings really more painful than other insects, like honeybees? And how do scientists “rank” the pain of an insect’s sting? Late entomologist Justin O. Schmidt made it his mission to find out. 

By documenting the particular kind of pain inflicted by the insects he studied in detail, Schmidt was able to introduce in the early 1980s a kind of science no one had ever attempted before—one requiring that he be stung by as many insects as possible, and which would come to be known as the Schmidt sting pain index.

'Scientists are just kids that never grew up'

When Schmidt was around five years old in the 1950s growing up in Pennsylvania, a group of older boys dared him to sit on a thatching ant colony. 

These ants don’t sting, but they can break human skin with their sharp bites, spraying formic acid into open wounds. Within seconds, Schmidt remembers, he was swarmed by ants, all of them intent on attacking his posterior. 

He did what anyone would do. Schmidt leapt off the anthill, took his off pants as fast as he could, and spent the next few agonizing minutes swatting anything that moved. 

“No long-term damage was done,” Schmidt wrote in his book, The Sting of the Wild: The Story of the Man Who Got Stung For Science, “but I had learned an important lesson: insects can fight back.”

Getting stung for science

Over the next 70 years, Schmidt dedicated his life to studying that truth, eventually getting stung by more than 150 species of insect, including bullet ants, warrior wasps, and giant Bornean carpenter bees.

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But Schmidt, who died in 2023, was no thrill- or attention-seeker. Rather, he used his body and its reaction to pain as a scientific instrument. 

This is because all venom—whether it comes from wasps, snakes, or jellyfish—can be said to be made up of two general parts. There’s the pain it causes, and there’s it’s toxicity. And while toxicity, or the physical damage done by a venom, is rather easy to compare scientifically, subjective pain is not.

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“There were no physiological or pharmacological methods to place accurate values on pain,” wrote Schmidt. 

Even today we lack reliable methods to insert electrodes into nerves or parts of the brain to measure pain, and then to understand the meaning of the electrode readings.

“Pain, in humans, is still very difficult because what some people experience doesn’t seem to be what all people experience,” says Corrie Moreau, an entomologist and curator at Cornell University. 

However, by using the widely available honeybee and its sting as comparison, Schmidt began to rank every other sting on a scale of zero to four, with the honeybee scoring a two. He also verified his estimates by encouraging other experts to do the same. And so, the Schmidt sting index was born.

“A lot of people now reference the Schmidt sting pain index,” said Moreau, who is also a National Geographic Explorer. “For the first time, it gave us the ability to sort of quantify and say which stings are more painful or longer lasting than others.”

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Many people will find it surprising to learn that yellowjacket stings are equal to those of a honeybee, despite wasps having a reputation for hurting more than bees. And both species, which scored a two, exceed the pain of fire ants and paper wasps, which only score a one. Only three animals tip the scale at scores of four, including tarantula hawk wasps, warrior wasps, and the appropriately named bullet ants.

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For his part, Schmidt liked to include notes about the particular kind of pain inflicted by each of the insects he studied. And for yellowjackets, he described the sting as “hot and smoky, almost irreverent,” and comparable to “W.C. Fields extinguishing a cigar on your tongue.”

Likewise, Schmidt described the honeybee sting as “burning” and “corrosive,” as if “a flaming match head lands on your arm and is quenched first with lye and then sulfuric acid.” 

For the warrior wasp’s tasting notes, Schmidt even got a little introspective: “Torture. You are chained in the flow of an active volcano. Why did I start this list?”

Why we study the science of pain

Studying how insect sting pain varies across species can help us learn about evolution. After all, insects had to evolve the ability to sting, and their continued ability to do so is only a result of an arms race with the predators they live near. 

“Ironically, stings must sometimes fail if they are to become effective defenses,” wrote Schmidt. “If yellowjackets had no predators, their venomous stings would never have evolved in the first place.”

Chris Alice Kratzer, entomologist and author of The Social Wasps of North America, also points out that predators can’t learn from a sting if they’re dead.

“Causing a predator to remember a painful encounter is often more valuable to a would-be prey insect than killing a predator outright,” Kratzer says. “For most animals, learning is only valuable to the living.”

Of course, as Schmidt’s pain index reveals, no two insect stings are identical. Each is the product of countless predator and prey interactions, natural selection, and eons of time.

In the end, while most of us would rather avoid being stung by a yellowjacket or any other stinging insect, Schmidt knew that insect sting pain was fleeting. 

Unless you’re allergic, for most stings, he recommended setting a 15-minute timer, at the end of which the pain should be well on its way to receding. 

Insect stings are “sort of like eating a habanero chili,” he said, indicating that pain does not necessarily coincide with damage. “Your tonsils don’t fall out after you’ve eaten it.” 

But the knowledge one can gain from being stung—either about an animal’s evolution and how it fits into its environment—that can stay with you for a lifetime.