As It Happens

This ant can snap its jaw 700 times faster than the blink of an eye

Behold the Myrmoteras trap-jaw ant, which can snap shut its spring-loaded mandibles in half a millisecond. Entomologist Fred Larabee explains how it works.
Researcher Fred Larabee says the Myrmoteras trap-jaw ant can snap its mandibles 700 times faster than the blink of an eye. (Steve Shattuck/Smithsonian Institute )

Story transcript

Behold the Myrmoteras trap-jaw ant, which can snap shut its mandibles around its unsuspecting prey at a speed up to 80 kilometres per hour.

"It's what we call a spring-loaded system," entomologist Fred Larabee told As It Happens guest host Susan Bonner.

"By incorporating latches and springs into a movement, these animals are able to generate speeds that are much, much faster than they would be by direct muscle action."

The whole thing takes half a millisecond, Larabee said. That's 700 times faster than the blink of a human eye.

Larabee, a post-doctoral fellow at the Smithsonian's National Museum of Natural History, is the lead author of a scientific paper on the snappy critters published this week in the Journal of Experimental Biology.

"It was very exciting. Nobody had ever studied these particular ants for their trap jaw before, so everything we were able to see was kind of new and exciting," Larabee said. 

The study provides the first mechanical description of the Myrmoteras' jaws — or mandibles, in insect terms.

"Instead of moving up and down like a jaw does in a vertebrate, they move side to side," Larabee — whose Twitter bio says he's "interested in insect mouthparts" — said.

Fred Larabee is a post-doctoral research fellow Smithsonian Institution National Museum of Natural History who studies insects' mouths. (Adrian Smith/YouTube)

Larabee and his colleagues captured and measured the effects of the ant's mandibles with a high-speed camera attached to a microscope.

"Once you're able to slow things down with a high-speed camera, you see things you don't normally see with the naked eye," he said.

"And so we were able to see things like the spring structure, which we think is on the back of the head. Prior to the strike, you can see the whole back of the head sort of deforming."

To then understand the mechanics behind the lightning-fast snap, the researchers used something called a micro-computed tomography, or micro-CT, a three-dimensional X-ray imaging system.

"It's basically a CAT scan for very small specimens," Larabee said. "It allows you to visualize internal structures without actually damaging the specimen."

This micro-CT image shows the muscular structure inside the ant's head. (Smithsonian Institution National Museum of Natural History )

A lobe on the back of the ant's head compresses, he said, likely acting like a spring that stores the energy that powers the ants' mandibles.

Myrmoteras ants use their ability to hunt prey in the East Malaysian rainforest — tiny arthropods called springtails, which launch themselves into the air like fleas when they detect a threat.

Springtails — like grasshoppers, crickets and fleas — also use spring-loaded systems to power their leaps.

"So these ants, because they have such fast jaws, can catch these very fast prey," Larabee said.

But they're not the fastest. The Myrmoteras' distant cousin Odontomachus snaps its mandibles twice as fast.