Most of these creatures live in caves or oceans. But still some can be found right next to a person.

How they shine

The chemistry of their bodies is behind this entire process. The key to the glow is a reaction based on a compound called luciferin.

Luciferin produces light through oxidation by losing electrons in the presence of magnesium and adenosine triphosphate (ATP), a molecule that provides energy to cells. This reaction is also mediated by the luciferase enzyme. Fireflies have special light organs in their abdomens, where these reactions occur, containing a layer of crystallized uric acid that helps reflect and amplify light.

Why it is necessary?

Only in the last few hundred years have scientists begun to understand how some living things can emit light. One of the first to move in this direction was a member of the Royal Society at Oxford in the 17th century, who discovered that a bioluminescent fungus needed air to glow. Oxygen is one of the main components of this process.

Fireflies begin to glow early while they are still in the egg. Scientists hypothesize that They need it as a signal for predators – often a bright color is a sign of the presence of poison in the body, which other animals know very well. Some fireflies are actually poisonous because they secrete lucibufagin.

When fireflies complete their metamorphosis and reach adulthood, they develop new light organs. But the general system remains unchanged: Light comes from inside special cells located in the light organs on the underside of the body, coloring them yellow, orange, green and even blue.

These cells are brimming with luciferin and luciferase, as well as large numbers of mitochondria. These tiny organelles pump out the ATP that fireflies need to carry out chemical reactions. Fireflies turn their lights on and off due to the flow of oxygen entering these cells. Lack of oxygen means darkness.

This on-off process is important for fireflies to find the right breeding partner. Finding an insect’s mate can be difficult, and each flicker species has developed its own light signaling system, a specialized set that distinguishes it from others.

In fact, this makes bioluminescence a sort of Morse code for love, says Lynn Faust, an independent firefly researcher in Knoxville, Tennessee, USA.