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10 Interesting Facts About Fireflies

Last Reviewed and Updated on November 1, 2022

Fireflies are one of the most magical bugs on the planet; with their ability to glow, they can make quite a spectacle. But do all fireflies glow? And what is the purpose behind their bioluminescence? Learn it all and more in this list of interesting facts about fireflies.

1. There are more than 2000 species of fireflies

The Lampyridae, commonly known as fireflies, are a family of insects with more than 2000 described species. They are found across the globe in temperate and tropical climates.

2. Not all adult fireflies glow

One of the most prominent features of fireflies is their production of light. While all firefly larvae can produce light, the adults (the ones you see flying around glowing) of some species are not luminous at all.

3. Larvae glow to deter predators, adults to attract mates

All larvae have the ability to glow, this ability is used as a warning signal that the larvae are distasteful. Most adult fireflies also have the ability to glow, and they use glowing as a mating signal.

4. Femme fatale fireflies imitate the signals of other firefly species to attract and kill them

Photuris is a genus of fireflies with a deadly little secret. The female fireflies use mimicry; they imitate the light signals of other firefly species’ females in order to attract the males. Once the unsuspecting male arrives to mate, the femme fatale fireflies will kill it and eat it.

There are at least 64 species of these fireflies, all found in temperate regions of North America.

5. They are soft-bodied beetles

Fireflies may not always look the part, but they are beetles. They resemble other beetles in many aspects at all stages of their life cycle.

6. In some species of fireflies, adults have no mouth

This is one of the weirdest facts about fireflies. European glow-worm, as well as some other species of fireflies, have no mouth. The adults emerge only to mate and lay eggs before they die.

Like weird facts? Also, read our list of 100 weirdest facts about animals.

7. Fireflies emit “cold light”

The light they produce emits almost no heat. Almost all energy produced by the firefly goes into producing light.

8. Fireflies that don’t glow attract mates with pheromones

As they don’t produce light to attract their mates, the non-bioluminescent fireflies use pheromones to attract mates. A pheromone is a chemical that triggers a social response in other members of the same species.

9. A firefly lays up to 500 eggs

Like all beetles, fireflies have a four-stage life cycle. A female will lay eggs, usually up to 100, but there can be many more. The larvae hatch from eggs. After a while, the larva will enter the pupa stage, and in the end, an adult firefly will emerge,

Fun fact: some firefly eggs are bioluminescent

10. The light is produced through a chemical reaction

A firefly has a special organ in its abdomen. In this organ, the light is produced through a chemical reaction for the most part combining luciferin, luciferases, and oxygen.

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