With global trade and travel, organisms are moved around easily and abruptly, causing biological invasions. What’s our best hope to combat these rapidly spreading pests? Sometimes, it’s to do the exact same thing, to start moving around organisms — on purpose — to attack unwanted pests. This is called ‘biological control.’ It is one of the most cost-efficient and environmentally acceptable long-term approaches for managing invasive species. And, it’s been a crucial component to managing the damage caused by the most destructive forest insect in U.S. history — the emerald ash borer beetle.