Facts About Fireflies

life of fireflies

Things you didn't know about these lightning bugs.
Common NameFireflies
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size relative to a paper clip

Fireflies make summer magical, but there’s more to learn about these bioluminescent beauties.
There are many wonders to behold in the animal world, but few offer such enchantment as that of a summer evening punctuated with the twinkle of fireflies. It’s a singular experience, like handfuls of Lilliputian stars tossed from the sky, falling to flit and hover among the grass and brambles. But behind their charming facade, fireflies are fascinating little insects. Consider the following facts:

they are beetles, not flies

Fireflies are familiar, but few realize that these insects are actually beetles, nocturnal members of the family Lampyridae. Most fireflies are winged, which distinguishes them from other luminescent insects of the same family, commonly known as glowworms.


Everyone knows how fireflies got their name, but many people don’t know how the insects produce their signature glow. Fireflies have dedicated light organs that are located under their abdomens. The insects take in oxygen and, inside special cells, combine it with a substance called luciferin to produce light with almost no heat.
Firefly light is usually intermittent, and flashes in patterns that are unique to each species. Each blinking pattern is an optical signal that helps fireflies find potential mates. Scientists are not sure how insects regulate this process to turn their lights on and off.

Firefly light may also serve as a defence mechanism that flashes a clear warning of the insect’s unappetizing taste. The fact that even larvae are luminescent lends support to this theory.


There are about 2,000 firefly species. These insects live in a variety of warm environments, as well as in more temperate regions, and are a familiar sight on summer evenings. Fireflies love moisture and often live in humid regions of Asia and the Americas. In drier areas, they are found around wet or damp areas that retain moisture.

Only some species produce adults that glow.

they are light geniuses

The light produced by the firefly is the most efficient light ever made. Almost 100% of the energy in the chemical reaction is emitted as light; in comparison, an incandescent light bulb only emits 10% of its energy as light, the other 90% is lost as heat.

Some species actually synchronize their flashes in a beautiful light show.

they are flashy flirts

Each species has a specific pattern of light flashing, and males use this pattern to let the ladies of the same species know that they would be a fine match for one another. When a female notices a suitable suitor, she replies with her own species-specific flash. Females may also use flash information to decide which male to mate with. And then, fireworks!

they come in a rainbow of colors

Well maybe not the whole spectrum, but they do come in yellow, light red, green and orange.

reproduction and diet

Females deposit their eggs in the ground, which is where larvae develop to adulthood. Underground larvae feed on worms and slugs by injecting them with a numbing fluid.
Adults eschew such prey and typically feed on nectar or pollen, though some adults do not eat at all.

their numbers are declining

If you’re seeing fewer fireflies each summer, you’re not alone. Anecdotal evidence suggests that firefly populations may be on the decline, most likely due to a combination of light pollution, pesticide use and habitat destruction. For example, according to Smithsonian.com, if a field where fireflies live is paved over, the fireflies don’t migrate to another field, they just disappear forever.

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compiled by

vishal kakade

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