Cool example of a bodypart/mechanism useful for both capturing prey and escaping predators
https://www.youtube.com/watch?v=M9VXGiYPLyM
Original article: Mandible-Powered Escape Jumps in Trap-Jaw Ants Increase Survival Rates during Predator-Prey Encounters
http://www.smithsonianmag.com/scien...elves-out-death-traps-their-mouths-180955237/
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https://www.youtube.com/watch?v=M9VXGiYPLyM
Original article: Mandible-Powered Escape Jumps in Trap-Jaw Ants Increase Survival Rates during Predator-Prey Encounters
Trap-jaw ants have specialized spring-loaded mandibles that snap shut at some of the fastest speeds ever recorded for an animal movement. Members of the genus Odontomachus, for example, are capable of snapping their mandibles shut as fast as 60 m/s and generate forces over 300 times their body weight [7, 8]. The trap-jaw apparatus has independently evolved at least four times in ants [9, 10] and is used for disabling fast or chemically-defended prey (e.g. springtails and termites) (reviewed in [11]).
[...]
Although all trap-jaw ants use their mandible strike for predation, in at least two lineages, this behavior has been co-opted for defense. Nest-guarding workers of Orectognathus versicolor and Odontomachus ruginodis direct their strikes against invading ants, flinging the attackers away from the nest entrance [12, 13]. During these interactions, the mandible strike occasionally causes the ant itself to be projected into the air. Although this “jaw jumping” has been observed in trap-jaw ants for over a century, it was generally assumed to be a coincidental byproduct of ants striking large or immovable objects [13, 14]. More recently, Patek et al. [7] suggested that mandible-powered jumping in Odontomachus might also be an adaptive escape behavior.
http://www.smithsonianmag.com/scien...elves-out-death-traps-their-mouths-180955237/
The acrobatic battle begins with an ant’s fatal misstep. What appears to be a small indention in the sandy terrain is actually a death trap: a steep-walled pit engineered to funnel the ant to its doom. Lying concealed at the bottom is a real-life sarlacc, the antlion. Its hairy, bulbous body tapers into a low-hanging, beady-eyed head that is seemingly weighed down by two massive spiked mandibles. Those mandibles peak out of the sand like a bear trap, ready to snap shut around a hapless victim.
Once in the trap, an ant will inevitably try to clamber out, oftentimes to no avail. The sandy walls collapse beneath it, and each step forward leads to two steps back. If the ant seems to be making headway, the antlion will hurl sand at its victim from below, further destabilizing the pit walls and causing the ant to topple to the bottom. The antlion’s jaws snap, latching onto the struggling ant and pulling it down until the insect disappears from view.
[...]
Trap-jaw ants fell victim to antlions about one-third of the time. About half of the escapees made it by running out of the pits. In 15 percent of the encounters, however, the ants did indeed summersault away by snapping their jaws against the bottom or side of the pit. The ants only used this tactic after the antlion had made itself known in a failed attack, indicating that it might be a last-ditch emergency escape method. The jaw jumps also only worked part of the time—the willy-nilly launches sometimes caused the ants to fall back down into the bottom of the pit, and many jaw-jumping attempts failed to hit the hot spot necessary for propelling the ants to safely.
Still, the jaw-jumping trick does seem to make a significant difference. The researchers glued 76 ants’ mandibles together, preventing them from using their jaws to jump. Ants with unrestrained jaws were almost five times more likely to escape the antlion pit than those that were hindered by glue.
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