Lampyridae is a family in the beetle order Coleoptera, members of which are commonly called fireflies, lightning bugs, or glow worms due to their conspicuous nocturnal (or, more accurately, crepuscular) use of bioluminescence to attract mates or prey.
The firefly is capable of producing a "cold light" containing no ultraviolet rays, with a wavelength from 510 to 670 nanometers, pale yellowish or reddish green in color, with a lighting efficiency of 96%.