17 Firefly Fun Facts and How To Help Scientists Learn More!

In many places in the United States (and the world), fireflies signal the unofficial start of summer. I can remember many evenings in childhood spent catching flashing fireflies in jars set up as mini-habitats, with holes poked in for ventilation and grasses lovingly laid down as bedding. Despite our fascination with the flashy creatures, we knew very little about them. Turns out that fireflies are really interesting, and are worth learning about! Keep reading for 17 firefly facts that you might not have known, and consider participating in the firefly community science project linked at the bottom of the post!

General Firefly Facts

• Fireflies aren’t bugs or flies at all – they are beetles in the family Lampyridae.
• There are over 150 species of fireflies in the United States. Worldwide, there are around 2,000 species.
• Fireflies are found on every continent except Antarctica.
• When attacked by a predator, fireflies release a few drops of toxin laden blood – this encourages most other animals to stay away from fireflies as a source of food.
• As adults, some firefly species are predatory, while others are pollinators that feed on pollen and nectar.

Firefly Larvae Facts

• After mating, the female lays her eggs underground, where the larvae will feed for a couple of weeks, then emerge as adult fireflies. 
• Firefly larvae will hibernate during winter underground or under the bark of trees. When spring conditions are right, they emerge as adult fireflies to start the cycle of life over again.
• Firefly larvae prey on snails, worms and slugs, making them great helpers in your garden.
• When firefly larvae catch their prey, they inject them with a paralyzing agent that makes them easy to ingest.
• All firefly larvae GLOW, but not all fireflies do!

“Flashy” Firefly Facts

• The type of light fireflies produce is called bioluminescence. It’s a reaction that takes place in a special organ in the abdomen. The chemical luciferin combines with enzymes, oxygen and fuel to produce that firefly glow. 
• The flashes of different kinds of fireflies are distinct in color, number, pattern and time between flashes. Sometimes, you will be able to identify a specific firefly species by observing its flash pattern. This infographic from Mass Audubon can help you get started.
• Flashing is a mating behavior – male fireflies use them to signal that they’re looking for a partner, and female fireflies signal that they are “ready to mingle”! (Females only signal back to members of their own species, though!)
• One species of fireflies is cannibalistic. Photuris fireflies prey on other fireflies by imitating the flash pattern of female fireflies to lure unsuspecting males to their doom!

Facts About Fireflies & Humans

• Fireflies need dusk to signal when it’s time to flash. Light pollution from humans (porch light, landscaping lights, etc.) may be contributing to population decline in fireflies. Turn those exterior lights off at dusk in the summer to help fireflies out!
• Land development for human use may also be a contributing factor to firefly population decline.
• Scientists are mapping the locations of fireflies to learn about population trends. You can help them collect data by participating in the Firefly Watch community science project, right in your own backyard!

More Awesome Community Science Resources

• Not sure what a community science project is? Check out this blog post, Community Science Projects: How To Save the World, to learn more about them.
• Want more community science projects to do this year? Grab our freebie, “9 Hands-on Community Science Projects“.