How Long Do Fireflies Live?

Jeff Turner/CC-BY-2.0

Fireflies usually live only until they reach adulthood and mate. As larvae, they live for approximately one year, from one mating season to the next one. At that point, they reproduce and die.

Fireflies lay eggs that often emit a glow, just like the larvae and adults. Though some fireflies eat each other, many adult fireflies do not eat anything at all because they do not live long enough to need nutrition. The larvae feed on worms and snails. The light made by fireflies is extremely efficient since it does not produce any heat. Fireflies use their lights to communicate and to attract the opposite sex.