Ferocious ants bite like a bullet

[Guest guest]

By Elli Leadbeater

 

The ants in action

Trap-jaw ants bite with a force of over 300 times their own

bodyweight, new high-speed digital images have shown.

 

Their jaws spring shut at more than 100 km/h (66mph)- the fastest

recorded speed at which an animal can move its body parts.

 

The pictures also reveal these tiny creatures, native to Central and

South America, do more with their vicious jaws than simply giving a

nasty nip.

 

By biting the ground, the ants hurl themselves upwards when danger

looms.

 

A frosty reception

 

Uninvited visitors to a nest of trap-jaw ants can expect a vicious

response.

 

The ants are named after their characteristically long jaws, which

they use to hurl unfamiliar neighbours from their nests, cripple

prey, or deliver a brutal bite to anything they consider a threat.

 

Employing the same high-speed imaging methods as those used to film

flying bullets, an American research team now show that the jaws can

move at exceptional speeds.

 

" This is really by far and away the fastest recorded animal limb

movement " said lead researcher Sheila Patek, of the University of

California, Berkeley, who worked with ants from Costa Rica.

 

" The ants' jaws are relatively short, but they deliver such a

powerful bite because they can accelerate so quickly. It's simple

physics. "

 

Airborne antics

 

The new findings, reported this week in the journal Proceedings of

the National Academy of Sciences, also explain why the ants sometimes

bounce into the air when they bite.

 

" If they bite something which is too hard to be crushed or thrown

back by their jaws, the impact tosses them upwards " said Dr Andy

Suarez of the University of Illinois, a co-author in the study.

 

This recoil effect propels the biter onto a brief, haphazard flight

which ends in a crash landing several centimetres away.

 

Such a chaotic journey might seem uncomfortable, but the ants are

simply too light to be injured by their misadventures. In fact, Dr

Patek and her team have now shown that the ants sometimes perform the

flights voluntarily.

 

 

The ants' jaws are multipurpose tools

 

A new way to move

 

By biting the hard ground, rather than another animal, the ants can

propel themselves skyward whenever the need arises.

 

The impact throws their tiny bodies upwards. In effect, the ants are

using their enormous bite force as a means to suddenly take off.

 

This novel way to move may help them to escape predators such as

lizards, which attack very quickly and would not be discouraged by a

simple bite.

 

The popcorn-effect of many ants jumping at once might also serve to

confuse attackers.

 

" The results show us the surprising and interesting ways in which a

single mechanical system can be co-opted for such different

behaviors, " says Dr Patek.