Squirrelfish (Holocentrus adscensionis)

All squirrelfish have such large, adoring eyes because they are noctural. Most spend their days hiding in the dark, rocky crevasses of coral reefs, coming out only at night to hunt for food. Squirrelfish are known for an uncanny ability to click and grunt - these obnoxious noises are produced by vibrating their swim bladders, and can be used to communicate and ward off predators.