Tropical forests are full of “hidden” diversity: insects hidden within flowers, and tiny wasps hidden within those insects. The wasps are predators from within (called parasitoids). But sometimes the predators are killed by the prey! How? Hidden intracellular bacteria- and even viruses- may provide defenses and counter-defenses in both flies and wasps. To find out, we need to go to the rain-forests where all these species live.