Gabriele Barrocas | October 28th, 2024

An overview of defense mechanisms

Animals engage in various kinds of warfare to protect themselves from real or perceived harm. Some species of spiders and other insects deliver chemical toxins via stings or bites. Skunks and some scorpions spray odorous or irritant chemicals. The Malaysian exploding ant, native to Malaysia, Thailand, and Borneo, is arguably the most extreme example of nature’s defense mechanisms. When threatened, these ants literally explode, releasing a toxic, sticky substance in their wake that ultimately immobilizes their enemies.

The science of the exploding ant

The Malaysian exploding ant has two oversized mandibular glands — secretory organs that release pheromones and other chemical compounds — that run down the length of its body. In the ants, these glands are filled with poison, providing their owner with a defense mechanism that involves self destruction by authothysis, a suicidal altruism process where an animal destroys itself by internally rupturing. In this process, the reddish-brown workers contract their gaster, a part of their abdomen, so tightly that it ruptures, spewing a yellow goo with a spicy odor. The Malaysian exploding ant’s defense mechanism serves as a reminder that evolution has selected a variety of strategies, from the subtle to the extreme, to ensure survival in the face of danger.

References

Laciny, A., Zettel, H., Kopchinskiy, A., Pretzer, C., Pal, A., Salim, K.A., Rahimi, M.J., Hoenigsberger, M., Lim, L., Jaitrong, W., Druzhinina, I.S. (2018). Colobopsis explodens sp. n., model species for studies on “exploding ants” (Hymenoptera, Formicidae), with biological notes and first illustrations of males of the Colobopsis cylindrica group. ZooKeys 751: 1-40. https://doi.org/10.3897/zookeys.751.22661
Weisberger, M. (2018, April 19). Exploding Ants Kill Foes, and Themselves, with a Blast of Toxic Goo. livescience.com. https://www.livescience.com/62354-exploding-ants-new-species.html