A newly discovered species of ant may look harmless on the outside, but inside these insects are ticking time bombs. When attacked, Colobopsis explodens ants live up to their name—they explode! The blast releases poisonous yellow goo that stops their enemies in their tracks.

C. explodens are found in the tropical jungles of Borneo, an island in Southeast Asia. They live in colonies of thousands, high up in the treetops, says Alice Laciny, an entomologist who studies insects at the Natural History Museum in Vienna, Austria. She and other scientists recently identified 15 species of exploding ants, including the previously unknown C. explodens.

Ant colonies can contain several queens that lay eggs, along with workers who care for the queens and their young. Colonies also have soldiers with large, plug-shaped heads and strong legs. Such features allow them to “act like living doors, barricading the nest entrances from the inside,” says Laciny.

If an ant encounters an enemy outside the nest, it unleashes its adaptation. Each ant has a sac inside its body filled with “sticky, toxic slime,” says Laciny. It latches onto an enemy and squeezes its own abdominal muscles hard enough that its backside bursts open, releasing the goo. C. explodens sacrifices itself to kill its rival with its deadly chemical attack.

The ants’ defense, though, makes them difficult to study without killing them, explains Laciny. “You need to be very careful collecting them. I’ve found that just a touch with the finger can be enough to make them explode,” she says.