The surprising reason why insects circle lights at night: They lose track of thesky

It's an observation as old as humans gathering around campfires: Light at night can draw an erratically circling crowd of insects. In art, music and literature, this spectacle is an enduring metaphor for dangerous but irresistible attractions. And watching their frenetic movements really gives the sense that something is wrong- that instead of finding food and evading predators, these nocturnal pilots are trapped by a light.