Biting the Bullet: Defense Mechanisms of Bullet Ants (Paraponera clavata)

Being stung by a bee was one of the more unpleasant experiences in my life. I can still remember the lingering pain even after removing the stinger *ouch*. Entomologist Justin Schmidt compiled the sting pain index-which ranks pain on a scale from 0 to 4 to gauge the effectiveness of insect defense mechanisms (The Word, 2007). The honeybee scores 2 and is the benchmark against which all insect stings are measured. In other words, a bee sting ranks fairly average on the sting pain index.

Behold, the Bullet Ant ( Paraponera clavata), best known for its giant size (18-25mm) and unusually severe sting, giving it a 4+ rating on the sting pain index, making it the most debilitating sting known for any insect.


Paraponera clavata  Misahaullí, Napo, Ecuador

Paraponera clavata


Bullet Ants resemble stout, reddish-black wingless wasps and they can be found in South America, particularly Atlantic coastal lowland rain forests, the Amazon River Basin as well as Costa Rica and Peru. Natural enemies of the Bullet Ant include other ant species and parasitoid Phorid flies (Morgan, 2012).


Paraponera clavata foundress queen foraging along the Amazonian forest floor.  Jatun Sacha reserve, Napo, Ecuador

Paraponera clavata foundress queen foraging along the Amazonian forest floor


So how exactly does the Bullet Ant react to perceived threats? As mentioned earlier, the Bullet Ant has a large well-developed sting which can be used offensively during foraging and defensively for protection. When their nest is disturbed, defenders swarm out, releasing pheromones- a chemical substance that can influence the behaviour of other members of the colony, alerting them of impeding danger (Janzen & Carroll 1983). The Bullet Ants then proceed to mercilessly grab and impale intruders. Additionally, the Bullet Ant boasts abdominal stridulatory (sound producing) organs. When it is disturbed or threatened, the Bullet Ant will let out a high-pitched shriek (yes it shrieks!) to alert the rest of the nest (Morgan, 2012).

Scary things do come in small packages, you have been warned.

(297 words)


  • The Word. 2007. The Word: Sting pain index. New Scientist, 195, 46.
  • Morgan, C.R.2012.  Giant Tropical Bullet Ant, Paraponera clavata, Natural History and Captive Management. Sonoran Arthopod Studies Institute.[online] Available at: <>. Accessed 10th April 2013.
  • Janzen, D.H. & Carroll, C.R.1983.  Paraponera clavata (Bala, Giant Tropical Ant). Costa Rican Natural History (Janzen, D.H., ed.), Univ. Chicago Press, Chicago, pp.752-75.

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