When ecologist Jose Valdez and his team released 10,000 tadpoles to populate a new conservation site in Newcastle, Australia, they surrounded the area with a mesh fence to keep out hungry snakes, birds and mammals. But they hadn't considered much smaller predators: diving beetles. The researchers soon began to witness the insects' violent attacks, and three years later only a handful of frogs remained. In two recent papers, Valdez, a researcher at Denmark's Aarhus University, and his colleagues documented the beetles' devastating predation tactics and possible implications for conservation efforts.