Trap-jaw ants use their powerful jaws to leap out of danger and escape hungry predators. The latest study, published in the open-access journal PLOS ONE, found their jaws increased their survival by two-fold.
Trap-jaw ants, though small, are able to hold their own in the animal kingdom as they have one of fastest bites ever recorded. Their jaws, known as mandibles, are capable of snapping as fast as 60 meters per second (134 miles per hour)—which, as the Guardian points out, is 2,300 times faster than the blink of an eye. These ‘spring-loaded’ mandibles generate forces over 300 times their body weight, thanks to the contracting muscles in their head.
While trap-jaw ants’ ability to use its mandible to jump has already been observed, researchers investigated whether the leaping behavior was used as a defensive strategy to escape predators and if the jumping increased their likelihood of survival. For the study, researchers placed trap-jaw ants into sand pits with one of their deadliest predators—the antlion.
These antlions are ‘sit-and-wait’ predators that capture their prey by first building pits in sand or fine soil and then waiting for their unsuspecting victims at the bottom, which you can see in the video below. You wouldn't want to fall into these pits, as their instability would thwart most escape attempts and would instead make you stumble towards the antlion. As if that wasn't terrifying enough, antlions throw sand at their prey, grab them and pull them in for a rather unpleasant end.
Researchers conducted 117 trials, where trap-jaw ants faced off with antlions that were starved for 48 hours. The study showed that trap-jaw ants were able to leap out of the sandpits 15% of the time, and the remaining 50% ran out of the pit. Researchers found that the size of the ant and the diameter of the pit had no impact on the frequency of escapes.
In a second series of experiments, researchers glued the mandibles of trap-jaw ants and dropped them into pits with antlions.
“They couldn't jump at all. It cut in half their survival rate,” says co-author Fredrick Larabee in a statement. Larabee says the results show 'evolutionary co-option,' as the function of the mandible doubles for both offensive and defensive mechanisms.
"In this case a tool that is very good for capturing fast or dangerous prey also is good for another function, which is escape," he added.