Why do Fireflies Shine?

You might be lucky enough to spot the magical insects known as fireflies if you have ever run through the grass or heard crickets chirp outside on a warm summer evening. They can be seen flashing their small yellow-green lights. Yet how do they shimmer so brilliantly?  

Although their blinking seems random, nothing could be farther from the truth. Fireflies’ blinking is a special language caused by a process called bioluminescence. (bye-oh-loom-en-ESS-ence).

Their shining is a courtship code. When a female flashes her light, the male will answer her by doing the same thing. Then they will mate if they like each other enough. Of course, adult fireflies are not the only ones who glow. Eggs, larvae, and pupae do to deter predators.

The way fireflies light up is one of the most famous examples of bioluminescence in the animal kingdom. Different chemicals mix in their bodies to produce light. According to Scientific American, they shine after producing a “mixture of oxygen, calcium, adenosine triphosphate (ATP) and the chemical luciferin in the presence of luciferase.” However, this light does not give off heat because it would kill the insect if it did.

fireflies in the meadow at dusk
Fireflies in the meadow at dusk by VAN Masha.

When you spot a firefly, remember that its ability to shine is a very exceptional language of love. While at face value, this awe-inspiring glow can be so mesmerizing, fireflies and their flickering represents nature’s amazing adaptation to evolve and survive! 

As Ralph Waldo Emerson said, “The invariable mark of wisdom is to see the miraculous in the common.”  There are many natural wonders outside still waiting to be discovered, and you can start by observing them in your own backyard. Watching for fireflies is nothing short of enthralling.      


Read more articles from Why? – Series on the Zealousness blog Why? – Series – iN Education Inc. (ineducationonline.org).



  1. Books, Time-Life. 1988. Insect World. Alexandria, Va.: Time-Life Books.
  2. Branham, Marc. How and Why Do Fireflies Light Up?” Scientific American, 5 Sept. 2005, www.scientificamerican.com/article/how-and-why-do-fireflies/#:~:text=When%20oxygen%20combines%20with%20calcium.
  3. “About Firefly Habitats & Where Your Can Find Fireflies Living.” n.d. Firefly.org. https://www.firefly.org/firefly-habitat.html.
  4. Yoest, Helen . 2020. “Fun Facts about Fireflies!” Bee Better Naturally with Helen Yoest. July 18, 2020. https://www.beebetternaturally.com/blog/2020/7/18/fun-facts-about-fireflies#:~:text=Some%20firefly%20eggs%20emit%20a.



Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Click to visit Centrion Services website
Battle of the Teal showcase ad
Visit program page

Most Recent Posts

Contact us
Contact us
On Key

Related Posts