The spring-loaded mouth of the trap-jaw ant (genus Odontomachus) is one of the fastest moving body parts in all the animal kingdom. The insects use them to protect their nests, spreading their mandibles apart and then snapping them together at speeds up to 230 km per hour and hurling invading species into the air. Now, researchers report that the ants can also use their jaws to hurl themselves into the air to escape predators, giving them a significantly better chance for survival. The team placed single trap-jaw ants into plastic cups filled with 4 cm of sand and a 1-cm-long burrowing insect with large jaws—known as an antlion—at the bottom. During their larval stage, the antlions burrow in fine sand, forming a pit above them. The steep and unstable walls of the pit can prove challenging to climb for unfortunate ants who venture too close—a problem compounded by the fact that the antlion will throw sand at their prey before pulling them beneath the surface. As seen in the video above, many ants did execute successful jumps by striking their jaws against the ground and blasting themselves into the air before being captured by the antlions. Out of 117 trials, the trap-jaw ants jumped their way to safety about 15% of the time and doubled their odds of survival by doing so, the team reports today in PLOS ONE. Not all jumps resulted in escape; some propelled the ant farther down the pit to their demise. For the ants, it seems, the best defense started out as a good offense.
(Video credit: Larabee FJ, Suarez AV (2015) Mandible-Powered Escape Jumps in Trap-Jaw Ants Increase Survival Rates during Predator-Prey Encounters. PLOS ONE 10(5): e0124871)