Getting Stung for Science

The first time Justin Schmidt got stung by a type of wasp known as a tarantula hawk, he thought he was going to die. He describes the pain as “shockingly electric,” like a “running hair dryer has been dropped into your bubble bath.” His advice if you were to get stung by one of these wasps? “Lie down and scream.”

As an entomologist at the Southwestern Biological Institute in Arizona, Schmidt studies the behavior of stinging insects such as ants, bees, and wasps. He travels the world in search of live specimens. He will shimmy up a tree to snatch a wasp’s nest or scoop an ant colony from the earth with his bare hands. His curiosity has made him a frequent victim of insect attacks: In his 43-year career, Schmidt says, he has been stung more than 1,000 times by 80 different species of insects.

At first, he figured that pain was just part of his job. But then he realized his experiences could help answer some puzzling questions. For instance: Why do some stings hurt a lot more than others?

To compare different kinds of stings, Schmidt created the Sting Pain Index. It ranks stings on a scale of 1 to 4, with 4 the most agonizing. “By putting numbers to the pain, I could begin to see patterns,” Schmidt says.

For example, the stings of solitary insects like the tarantula hawk often feel awful, but don’t do any real harm. On the other hand, insects that live in social groups, such as honeybees, tend to have moderately painful stings that are highly toxic. These observations told Schmidt that toxic stings are important defenses for social insects, which have to protect nests full of tasty larvae and sometimes honey. The pain of toxic stings is a warning to predators: Stay away or you could die.

“It turns out that pain is a very valuable mechanism for discouraging a predator from attacking you,” says Schmidt. But it’s a lesson that’s lost on him. “Pain to me is just a bluff.”

Use exponential expressions to compare the stings of insects at different levels on the pain scale.

Schmidt says the sting of an iridescent cockroach hunter feels like “a stinging nettle pricked your hand.” He ranks it a 1. How much more painful is the sting of a warrior wasp, which Schmidt ranks as a 4 and equates to being “chained in the flow of an active volcano”?

The sting of a baldfaced hornet ranks a 2 on the Sting Pain Index. It feels like “getting your hand smashed in a revolving door.” How much more painful is the sting of a red paper wasp, which ranks a 3 and feels like “spilling a beaker of acid on a paper cut”? 

The yellow jacket, a common wasp, has a highly toxic sting. It ranks a 2 on the Sting Pain Index. The sting of the largest velvet ant is less toxic, but ranks a 3 in terms of pain. How much less painful is a yellow jacket sting compared with a velvet ant sting? (Hint: When an exponent is negative, as in the expression 10^-x, you can rewrite it as 1/10^x.)

No known insect stings hurt more than a 4 on the Sting Pain Index. But if Schmidt were to discover a new insect whose sting is 100,000 times as painful as a honeybee’s 2, how would he rank it?