Animals often use highly specific signals to warn their herd about approaching predators. Surprisingly, similar behaviors are also observed among plants. Shedding more light on this phenomenon, researchers have discovered one such mechanism. Using Arabidopsis thaliana as a model system, the researchers have shown that herbivore-damaged plants give off volatile chemical 'scents' that trigger epigenetic modifications in the defense genes of neighboring plants. These genes subsequently trigger anti-herbivore defense systems.