Those pesky sugar ants invading your home? Be grateful you don’t live in the rainforests of Southeast Asia, where scientists have been studying a unique species of tree-dwelling ant whose defense mechanism consists of blowing itself up.
When confronted by a threat or a predator, Colobopsis explodens (natch) immediately ruptures its body to release a yellow, toxic, vaguely curry-scented goo that sticks to its enemy. Only worker ants, which are all sterile females, were found to explode.
“[The ants are] particularly prone to self-sacrifice when threatened by enemy arthropods, as well as intruding researchers," researchers wrote.
The first-ever report on C. explodens appeared in late April in the journal ZooKeys, along with an accompanying 10-minute video showing various clips of the ants going about their business in their natural habitat. It’s all part of the Exploding Ants project, a multi-year research enterprise by the Vienna Science and Technology Fund that aims to “identify a new and major type of interaction between dominant rainforest insects, their associated microorganisms and plants.”
C. explodens is the first new species of exploding ant to be described since 1935; the scientists were even able to sequence its DNA, along with that of the rainforest trees it was found on.
Among the nonworker C. explodens that don’t blow up, the researchers also found soldier ants with massive, plug-shaped heads specifically designed to block the nest entrance from predators. Looking like a post-apocalyptic sci-fi version of Birdo from Super Mario Bros. 2, the doorkeeper ants, as they’re called, exist solely for the purpose of using their huge heads to block the entrance to the nest in the face of a threat.
Self-sacrificing behavior like that seen in C. explodens, which is also seen in bees and some termites, is called autothysis, or “suicidal altruism.”
“Imagine a single ant is like a cell in a human body,” lead author Alice Laciny told The Washington Post. “The exploding workers work as immune cells. They sacrifice their lives to hold off danger.”
Also of note, the researchers were able to observe fledging male ants — the first male exploding ants ever seen, as most male ants only leave the nest in order to mate. Nests were observed both in trees and in an “in vitro” artificial setup within a clear-sided box, which can be observed in the Exploding Ants project video.
"While the exploding ants play a dominant role in rainforests, their biology still holds a number of secrets," researchers wrote in a release. "The observations and experiments conducted on the newly described species have laid important groundwork for future research that will uncover even more details about these enigmatic explosive insects."