It happens every year, but it's still an illuminating sight to behold. Fireflies in the woods of Great Smoky Mountains National Park put on their annual synchronous light show. This week is the peak ...

KELLETTVILLE, Pa. ― Every year in late June, Peggy Butler and her husband, Ken, welcome visitors to rural northwestern Pennsylvania for the chance to glimpse the rare and beguiling Photinus carolinus.

List of species by scientific name -- Preface: For the awe of it -- Acknowledgments -- What genus is it? -- Fireflies around the world -- Frequently asked questions -- Eggs, larvae, and pupae -- ...