Fireflies, also known as lightning bugs, are nocturnal, luminous beetles of the family Lampyridae. These names come from the fact that some species as adults emit flashes of light to attract mates, using special light-emitting organs in the abdomen. The enzyme luciferase acts on luciferin to stimulate light emission. This reaction is of scientific interest, and genes coding for these substances have been spliced into many different organisms.
Many species, especially in the genus Photinus, are distinguished by the unique courtship flash patterns emitted by flying males as they search for females. Photinus females generally do not fly, but give a flash response to males of their own species.
Many species of lampyrid beetles do not glow as adults, but they all glow as larvae. The larvae of fireflies are generally known as glowworms -bioluminescence serves a different function in lampyrid larvae than it does in adults. Larval bioluminescence appears to be a warning signal to predators, since many firefly larvae contain chemicals that are distasteful or toxic.
There are more than 2000 species of firefly, found in temperate and tropical environments around the world.