Every June, fireflies light up the Smoky Mountains with their exuberant courtship displays – sure, it all seems very romantic. But a few years ago I spent some weeks with colleagues studying the predators that take advantage of these dense breeding aggregations. We knew that certain insectivores – like birds and lizards – avoid eating fireflies because they’re toxic. So we didn’t expect to find many predators enjoying this luminous feast. Little did we realize how gore-filled that summer would turn out to be!*