for National Geographic News
A new speed record has been set in the animal kingdom, scientists say.
A species of tropical ant snaps its jaws together at an astonishing 145 miles (233 kilometers) an hour, using the force of that motion not only to capture prey but also to catapult to safety, according to a new study.
The study establishes that the ants have adapted a structure normally used for feeding for a completely different purpose: propulsion.
Trap-jaw ants have the fastest self-powered strike in the animal kingdom, outpacing speed demons like the whip-fast chameleon.
(Read "'Catapults' Give Chameleon Tongues Superspeed, Study Says" [May 2004].)
"In terms of basic engineering, ants have solved this incredible problem of producing force using very simple structures at a very small scale," said Brian Fisher, co-author of the study and curator of entomology at the California Academy of Sciences in San Francisco.
"They use their mandibles [jaws] to feed, of course, but they've also turned this feeding mechanism into a mechanism to escape predators," he added.
Fisher and his colleagues published the study today in the early online edition of the Proceedings of the National Academy of Sciences.
The study clears up a basic question about this species: Why do these ants have jaws that can generate such extremes of force and acceleration?
"It's not like they're trying to catch a cricket that's so fast they need this high speed, so there's a conundrum there," Fisher said.
"Now we've found there's a dual function. It may be that a very important aspect of their life history is escaping from an enemy."
SOURCES AND RELATED WEB SITES