Why and how fireflies light up
Lightning bugs and fireflies are one and the same insect, a kind of beetle. You’re most likely to see them in warm weather, when rainfall has been plentiful. Many a child has spent a summer evening chasing fireflies. And maybe you’ve wondered, why do fireflies light up? And how do they do it?
Let’s talk about the how first. The light of a firefly is a chemical reaction caused by an organic compound in their abdomens. The compound is called luciferin. As air rushes into a firefly’s abdomen, it reacts with the luciferin. It causes a chemical reaction that gives off the firefly’s familiar glow. This light is sometimes called cold light because it generates so little heat.
According to Firefly.org:
Scientifically, fireflies are classified under Lampyridae, a family of insects within the beetle order Coleoptera, or winged beetles. There are estimated to be 2000+ firefly species spread across temperate and tropical zones all over the world.
Fireflies light up for safety
The firefly can regulate the airflow into the abdomen to create a pulsating pattern.
And that brings us to the why.
Some experts think the firefly’s flashy style may warn predators of the insect’s bitter taste. On the other hand, some frogs don’t seem to mind the flavor. They eat so many fireflies that they themselves begin to glow.
Male fireflies also light up to signal their desire for mates, and willing females attract the males with flashes of their own.
But not all the flashing of fireflies is motivated by romance. While each firefly species has its own pattern of flashing, some females imitate the patterns of other species. Males land next to them, only to be eaten alive.
So the next time you see a firefly, keep in mind that its flickering isn’t just a wonder of the night. It’s also a unique, and sometimes deadly, language of love.
Photos from the EarthSky community
Bottom line: Fireflies – aka lightning bugs – light up because of a chemical reaction between an organic compound in the fireflies’ abdomens – called luciferin – and the air.