Clown fishes live their entire adult lives nestled in the protective arms of a single sea anemone on a coral reef. Between birth and adulthood, however, the fishes have to complete a treacherous journey. After hatching, a larva—a tiny, partially formed version of an adult fish—swims out of the reef to the open sea to finish developing, presumably away from predators. After maturing for 11 to 14 days, the juvenile is ready to swim back to the reef and select an anemone to call home. But as it swims close, it has to cross a “wall of mouths”—all kinds of creatures, such as wrasses and lionfish, that lurk along the reef ready to gobble up the tiny fishes. Most successfully navigate the gauntlet by recognizing the smells of the predators and avoiding their grasp.