How & Why Does a Firefly Glow?

... Ashwin/sienceabc:

The secret by which fireflies are able to light up lies in their abdomen. Fireflies contain a special light emitting compound in its abdomen called luciferin. When luciferin and an enzyme luciferase reacts with oxygen a chemical reaction occurs, this reaction results in the lighting up of firefly’s body. The wavelength of light emitted by fireflies are in the range of 510-670 nanometers (pale yellow to reddish green colour).

The light generated by firefly is called “cold light” as the heat generated is very little. This is good for the firefly as its body would not been able to survive if it generated heat like a light bulb. The process through which fireflies light up their bodies is called bioluminescence. A firefly is not the only creature who has this ability. Many other organisms, mostly sea and marine organisms, can also produce their own light.

Why Fireflies light themselves up?

Fireflies, unlike most other animals with bioluminescence, can turn on and off its light. So why does a firefly keep on turning on and off its lights.

Though it is not clear how exactly fireflies are able to switch on and off their light, scientists believe that they are able to control the bioluminescence by regulating the airflow of oxygen into abdomen by sending signals from their brain to a special light emitting organ in their abdomen.

Fireflies come into the world as larvae, knowing how to glow and they talk about lighting up the world from birth. The bioluminescence though, serves different purposes in larvae and adult fireflies. In larvae the main purpose of glowing is to avoid predators. Fireflies contain a nasty tasting chemical called lucibufagens which can be pretty toxic to the predators. So when a firefly glows, the predator realizes that it’s going to unleash its nasty toxic chemicals.