For home gardeners and farmers, herbivorous insects present a major threat to their hard work and crop yields. The predator insects that feed on these bugs emit odors that pests can sense, which changes the pests' behavior and even their physiology to avoid being eaten. With bugs becoming more resistant to traditional pesticides, researchers now report they have developed a way to bottle the "smell of fear" produced by predators to repel and disrupt destructive insects naturally without the need for harsh substances.