The ants are native to Southeast Asia. The two Myrmoteras species in Larabee’s study were collected in Malaysia, where they live among leaf litter on the island of Borneo.
They’re one of several types of trap-jaw ants, some of which have more powerful jaws. But the mechanics of the ants in Larabee’s study were less well known. So he and his colleagues put the insects under a micro-CT scan and filmed them with a high-speed camera that captured 50,000 frames a second to reveal their movements.
“Their heads are very strangely shaped and they have this really prominent lobe on the back of the head,” he said. “While the mandibles are locked open, the closer muscle is able to supply tension to that spring in the back of the head.” When the jaw releases, “You can see that structure sort of caving in on the head. There’s a very clear deformation.”
RELATED: Giant Larvaceans Sweep Up and Poop Out Plastic Waste in the Oceans
Larabee and his colleagues published their findings today in the Journal of Experimental Biology. The high-speed camera helped them pinpoint the speed of the jaws, while the CT scanner — which uses X-rays to produce a 3D image — “was really useful to look at the structures.”
“It’s a great tool for studying insect anatomy because you can resolve really small, delicate features of internal anatomy without having to break open the specimen,” Larabee said. “Being able to visualize that in a 3D environment is even more beneficial, because you can digitally dissect different parts and visualize just the pieces you’re really interested in.”
And it turns out trap-jaw ants have “completely different structures” to slam their mouths shut than other species.
“It’s a really great example of how evolution can come up with multiple solutions to the same problem,” he said.
WATCH: Predator vs. Prey on the African Savanna