This trap-jaw ant’s (Odontomachus brunneus) mandibles can slam shut at speeds exceeding 40 meters per second. They come in handy for capturing prey, protecting itself and more mundane tasks like digging or taking care of ant larvae.
Researchers have now discovered another use for them – evading danger. Previous studies have shown trap-jaw ants could sometimes jump with their jaws. “But it was unknown whether this behavior was meant to help them get away from a predator, and it wasn’t clear that it actually improved their odds of surviving an encounter with a predator,” said Fredrick Larabee, one of the authors of a new study.
The researchers placed trap-jaw ants into antlion pits to see if the ants’ jaws could help them escape from antlions.
“The ants were able to jump out of the pits about 15 percent of the time in their encounters with antlions,” Larabee said. “But when we glued their mandibles shut before dropping them in the pits, they couldn’t jump at all. It cut in half their survival rate.”
Check out the pair of videos below to see the trap-jaw ant in action.
But, the jump doesn’t always work.
While the mandibles helped, it wasn’t a guarantee. Out of 117 tests, the antlion left with a full stomach one-third of the time. Most of the time, the trap-jaw ants just crawled out of the pit.
Larabee says the videos above show how one capability that evolved for a particular use can be adapted. “In this case a tool that is very good for capturing fast or dangerous prey also is good for another function, which is escape,” Larabee said.
There are some lingering questions about the evolutionary history of the trap-jaw ants. There are more than 160 species of trap-jaw ants, and researchers have only studied a small fraction of them. “A full understanding of the evolutionary dynamics trap-jaw mandibles will require a more comprehensive documentation of the natural history of trap-jaw ants,” the authors write in their study.