When living creatures produce and emit light it’s called bioluminescence. The main reason fireflies glow is to find a mate, though they can also light up under other situations as a warning to others.
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How Swarms of Fireflies Sync Their Flashes - The New York Times
Blue Sky Science
Research in the news: Understanding the firefly's glow
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Buy Fireflies, Glow-worms, and Lightning Bugs: Identification and Natural History of the Fireflies of the Eastern and Central United States and Canada
Fireflies, Glow-worms, and Lightning Bugs: Identification and Natural History of the Fireflies of the Eastern and Central United States and Canada
How Do Fireflies Glow? Mystery Solved After 60 Years
How a firefly's tail makes light
How Do Fireflies Glow? Mystery Solved After 60 Years
How do fireflies get their glow? We finally have some answers.
Blue Sky Science - Morgridge Institute for Research
How Fireflies Glow (and What Really Turns Them On)
How do fireflies get their glow? We finally have some answers.
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