Mystery Solved: Scientists Finally Figured Out Just How Fireflies Glow

If you have ever seen fireflies flashing in the darkness, you know they can give a sense of magic to a warm summer evening. The secret to their mystical glow, however, is not magic. Scientists have recently discovered the chemicals behind these pretty lights you can see against the night sky.

Facts About Fireflies


Fireflies are not actually flies but beetles, points out Melissa Breyer at Mother Nature Network. Not all of the over 2,000 firefly species have the ability to generate light, but those that do use it to attract mates. Some firefly larvae can light up as well, which they use as a deterrent to predators, according to Sarah Zielinski of the Smithsonian. Their glowing colors include not only yellow, but also orange, blue, and green. Adult firefly diets range from pollen and nectar to other fireflies.

How Fireflies Glow

Scientists have long known that the firefly's bioluminescence is caused by a chemical called luciferin combined with other elements, explains National Geographic. Research now confirms what chemical reaction creates the glow: a special form of molecular oxygen with an extra electron combines with the luciferin to create the light. Scientists call the oxygen molecule a superoxide anion, and it may be a key to how other species exhibit bioluminescence in nature.

Visual Demonstration

Scientists have been able to replicate a firefly's glow in laboratory conditions, as a video produced by the American Chemical Society shows. The video also explains that understanding how firefly luminescence works may have medical applications in using marker molecules to visualize where bacteria or tumors are in living organisms.

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Knowing how a firefly emits its light in no way detracts from the fascination of watching a swarm of fireflies on a summer night. Step outside into the darkness, locate the winking light of fireflies, and marvel at one of nature's wonders. Meanwhile, help preserve these and other natural miracles by donating to the Rainforest Site.

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