It’s nighttime and you’re sitting outside around a campfire looking up at the stars and the trees and suddenly you see a tiny blinking light. You think to yourself: did I really just see that? What was that? You see it again and again, then another and another… Are they aliens? Could these lights be fairies? Then you realize you’re surround by hundreds of fireflies!
Your backyard transforms into a whole new world at night! These glowing insects (actually beetles) are some of the most interesting bugs out there. Here’s why!
How to Glow: Firefly Style
Fireflies have a light organ below their abdomen which contains a chemical reaction allowing the firefly to create light.
[Chemical reaction: Oxygen + Ca + Energy (ATP) + a special compound called luciferin. When this compound gets eaten by an enzyme (luciferase), the firefly can produce its own light.]
Light created by living things through biochemical reactions is called bioluminescence.
Bioluminescence is efficient; all the energy is turned into light and not heat! Think about the lightblubs in your home, they produce light but if you’ve ever touched one that was turned on for awhile you know it gets hot too! Fireflies don’t just produce yellow light, like we commonly see. Different species of fireflies can produce red, green and orange! These beetles have full control over their light organ and can turn it on and off as they please. This allows the fireflies to use their blinking butts for different purposes.
Why Glow At All?
Fireflies glow to communicate. Here is what they are saying:
1. “DON’T EAT ME”: Fireflies have a chemical in them that makes them taste badly to other animals. When they light up this tells predators “Hey if you eat me you’re going to feel really sick.” This is a very effective warning sign.
2. “THIS IS WHO I AM”: There are 2,000 different species of fireflies and each species has a unique flashing pattern to let other fireflies know who they are. This helps them find other fireflies of the same species.
3. “HEY, I’M LOOKING FOR A MATE”: The flashing patterns are not only for telling the difference between species, but males and females also have different flashing patterns! This is how females choose a mate. Once s female chooses a male firefly, she will sync to his flashing pattern.*
*Scientists have found that the faster and more frequent the flashing, the more attractive males appear to female fireflies!
More on Bioluminescence
What else uses bioluminescence? We are going to have to travel outside of the Biosphere into some of the darkest places on earth to see who else produces their own light.
First stop is the dark caves of New Zealand, home to thousands of glow worms! These creatures make the cave ceiling look like a starry night sky.
Below the ocean’s surface live bioluminescent algae called dinoflagellates. (These specific algae blooms are safe and non-toxic). You can find them off the coast of many places across the globe during certain times of the year.
The deepest depths of the ocean where the sun cannot reach may seem empty of life. The only light there is made by the creatures who call the deep ocean home. The angler fish, comb jelly fish, and vomiting shrimp are just a few of the species that produce their own light to help them survive.
Firefly Jokes For Your Family & Friends
Q: What did the firefly say to the other firefly when she left?
A: I’ve gotta glow now!
Q: What’s the opposite of a firefly?
A: A waterfall
Q: Why did the firefly fail his test?
A: He wasn’t very bright.
Activity: Catch Fireflies
1. Look for fireflies in the evening as they become active between June-August. They prefer wet and/or forested areas.
2. Have a jar ready to go for your firefly adventure. Carefully, or with the help of a parent, poke holes in the lid to allow airflow and place a moist paper towel at the bottom of the jar to keep the humidity.
3. Capture fireflies using butterfly nets. Make sure to be gentle, they are very fragile.
4. Once they are in the net, clamp the top of the net off with your hands after making sure the firefly is at the bottom.
5. Gently encourage the firefly into the jar by turning the jar upside down with the net underneath. Fireflies fly upwards, and should fly up out of the net into the jar.
6. Don’t keep a firefly in a jar for more than 10 minutes. Always release them at night when they are most active and able to easily get away from predators.
7. Ironically, don’t use any flash photography to take a picture of your fireflies. The bright lights can confuse and harm fireflies.
8. Happy catching!