Odontomachus

Genus of ants

Odontomachus is a genus of ants commonly called trap jaw ants found in the tropics and subtropics throughout the world.

Commonly known as trap jaw ants, species in Odontomachus have a pair of large, straight mandibles capable of opening 180°. These jaws are locked in place by an internal mechanism, and can snap shut on prey or objects when sensory hairs on the inside of the mandibles are touched. The mandibles are powerful and fast, giving the ant its common name. The mandibles either kill or maim the prey, allowing the ant to bring it back to the nest. Odontomachus ants can simply lock and snap their jaws again if one bite is not enough, or to cut off bits of larger food. The mandibles also permit slow and fine movements for other tasks such as nest building and care of larvae. The ants were also observed to use their jaws as a catapult to eject intruders or fling themselves backwards to escape a threat. The larvae of trap jaw ants are remarkable in being ornamented with long spikes and presenting dorsal adhesive pads for fixation onto internal ant nest walls. They are carnivorous, extremely active larvae. Apparently, they undergo three larval moults before entering metamorphosis.

Trap jaw ants are mostly carnivorous, but also consume nectar, insect honeydew, and ripe fruit.

Trap jaw ants of this genus have the second fastest moving predatory appendages within the animal kingdom, after the dracula ant (Mystrium camillae). One study of Odontomachus bauri recorded peak speeds between , with the jaws closing within just 130 microseconds on average. The peak force exerted was in the order of 300 times the body weight of the ant, and acceleration of 1,000,000 m/s² or 100,000 g.

The jumping spider genus Enoplomischus seems to mimic this ant genus.

Odontomachus species are found in Central and South America, Asia, Australia, and Africa. In the United States, O. haematodus was "recorded in Alabama back in 1956, but now researchers have officially confirmed that the species has spread across the Gulf Coast, at least as far east as Pensacola, Florida." In the past, O. ruginodis was thought to be confined to the Orlando region, but Magdalena Sorger, a PhD candidate at North Carolina State University, has confirmed a record of O. ruginodis more than 100 miles north of Orlando, in Gainesville, Florida. Odontomachus relictus, however, is only found in "endangered scrub habitat on central Florida’s ancient sand ridges."