More than 200 million people in the world are infected by the parasitic worms Schistosoma, which can cause a devastating, organ-damaging disease known as schistosomiasis. Although a safe and effective treatment exists, schistosomiasis has been challenging to control and eliminate. One of the major reasons why is that these worms can survive in the environment in freshwater snails, creating a persistent reservoir of parasites that can infect humans. In a recent study led by Stanford scientist Susanne Sokolow, a research team developed a new method to reduce transmission of Schistosoma infections by exterminating the environmental parasite reservoirs. Their strategy? Releasing river prawns to gobble up the snails that carry these worms.