Through a process known as bioluminescence, animals can produce chemical light. They use this light to achieve a variety of goals: to ward off predators, to act as decoys and to communicate. Fireflies, for example, light up their posteriors to find mates.
But other animals do not glow gentle into that good night. The ball dangling from an anglerfish's head, rich with glowing bacteria, is a source of fatal attraction. The anglerfish light beckons to fish in an otherwise inky sea, and curiosity kills - the fish are lured in and eaten.
Given that Cramer's worms had giant jaws (a sign of a meat-eating disposition), the entomologists believed the bugs' green glow might serve a similar purpose. To find out if the bugs were predatory, they offered up an ant to one of the worms. And, well, then this happened: