"Fireflies Flies, Bugs, or Beetles?
Fireflies are not really flies. Some people call them lightning bugs, but they are not bugs either. Fireflies are actually beetles. The firefly would be a rather ordinary beetle, except for one thing. At night, it can “light up.” You probably have seen fireflies whizzing around and flashing their lights on warm summer nights.
Some firefly larvae can glow, too. This is why people call them glowworms. Of course, they are not worms at all.
How Do Fireflies Make That “Cool” Light?
The firefly’s light is cool in more ways than one. Unlike natural and human-made light, it gives off no heat. The firefly’s light is produced by a complicated set of chemical reactions that take place in its abdomen. This complex process is called bioluminescence.
Fireflies can control the light they produce. They send out light in a pattern of flashes. Scientists believe that fireflies do this by regulating the amount of oxygen they take into their bodies. Oxygen is the fuel that helps create the light"