Harmless but hated, the ubiquitous earwig is a 'fascinating' bug with bad PR

Graham Thompson is a Western University entomologist and self-described "big-time bug guy."

He has no problem getting up close and personal with all sorts of creepy crawlies, including ones known to bite, sting, suck blood or feed off human hosts.

The omnipresent earwig doesn't do any of those things. Most of the time they're happy just to hide out of sight in dark damp places and avoid any human encounter. Still, Thompson admits that while he likes bugs, he finds earwigs unsettling. 

"Especially when I'm camping, I don't like them in my tent," he said. "Even though I know it's irrational because they're harmless." 

So why do people find earwigs so off-putting?

Thompson thinks it's an insect with an image problem, and that those long, pointy pincers have a lot to do with it. 

"They just look weird and not friendly," he said. "But they're not harmful to humans at all. It's purely an aesthetic dislike that people have of them. [The fear] is almost primal."

The pincers — called "cercai" — extend outward from the insect's abdomen and ramp up the earwig "ick" factor. "Pincher bugs" is a common nickname used for earwigs, even though they're not known to use the appendage to aggressively pinch people. Thompson said even if an earwig was motivated to pinch a person, the pincers aren't powerful enough to break the skin.

Sometimes earwigs will arch up their pincers when they feel threatened, another behaviour that doesn't endure them to humans. 

And while the pincers don't pack much pinching punch on people, Thompson said earwigs use them grab food and defend themselves against other insects. 

Not helping the earwig's public image is a false bit of folklore about them targeting sleeping humans.

"The story was that at night they would borough into your ear and deposit eggs into your brain, which of course is completely false but that's where the name comes from," said Thompson. 

Jeremy McNeil, an entomologist and biology professor at Western University, also often hears the "earwigs in ears" story. 

"If you find earwigs in your ears, you have got greater problems than earwigs," said McNeil. "If your ears are full of decomposing vegetation, then it's not the earwigs you should worry about."