Most animals, humans included, have bodily rhythms governed by the sun. But for nocturnal critters it's the moon that matters, affecting everything from lovemaking to lion attacks. Tungara frogs (Engystomops pustulosus), which live throughout Central and South America, call and mate at night. They usually prefer to be out and about when it's really dark, since illumination increases their risk of getting eaten. Folklore says that coyotes howl at the full moon, but it turns out they're more particular than that. Coyotes (Canis latrans) use three different types of howls: lone, group and group-yip howling. For the iconic lone howl, the phase of the moon makes no difference. Hundreds of species of coral spawn once a year in a mass synchronized event, releasing millions of eggs and countless numbers of sperm into the water a few nights after a full moon. The timing of spawning varies from species to species and by location. For instance, in Australia’s Great Barrier Reef, more than 100 of the 400-plus species of corals spawn simultaneously over the course of a few nights during spring or early summer.