Why don’t ​fireflies get hot when they glow? Why can’t we make anything as efficient?

The year 2009 was the birth of Owl City’s “Fireflies,” a song about a fight with insomnia of a twenty-two-year-old, which shot a six times platinum worldwide. The track outshined other songs and landed on the top of the UK singles chart for three weeks and continued to dominate in the years that followed. There’s something about its lyrics that made it the perfect feel-good track while going on a road trip, or on a lazy Sunday afternoon while you’re taking a break from a week’s work. (click here for more details)

Owl City (Adam Young in real life) who rose to prominence with his hit single was questioned by fans on the unclear lyrics, where he sings: “Cause I’d get a thousand hugs from 10,000 lightning bugs, as they tried to teach me how to dance.” One fan even aired his confusion on Twitter to ask whether “each firefly hugs you 1,000 times, or do the only 1/10th of the bugs give you a hug?”. Adam Young did the math to explain, but to conclude his rather lengthy answer simply: He was embraced 1,000 times by 10,000 luminescent insects”.

Fireflies are familiar. Many of us grow chasing these glowing insects and keeping them in glass jars. Their enchanting light sparked our childhood curiosity and captured our imaginations. As children staring at their flashing body, we can’t help but wonder, “How are these insects able to light up?” or “Do fireflies get hot when they glow?”.

Fireflies, which are sometimes called lightning bugs, are nocturnal beetles from the Lampyridae family. There are about 2,000 species of fireflies, most of them have wings, which distinguishes them from glowworms. Fireflies love warm, humid areas, so they thrive in tropical regions and temperate zones. They also live in forests, fields, and marshes. They need a moist environment to survive. (click here for more details)

We all know how fireflies got their name, but many of us are not quite familiar with how these insects produce their signature glow. Fireflies have dedicated light organs located under their abdomens. As they breathe, oxygen rushes into the fireflies’ abdomen and reacts with luciferin to produce light. In some firefly species, adults aren’t only the ones that glow but also the eggs. It was observed that firefly eggs flashed in response to gentle tapping or vibrations. (click here for more details)

There are two chemicals present in a firefly’s tail: luciferase and luciferin. Luciferin is resistant to heat and glows under the right conditions. Luciferase is an enzyme that triggers light emission.  Both the luciferase and luciferin light up in the presence of Adenosine Triphosphate (ATP). (click here for more details)

Luciferase and luciferin found in fireflies are medically and scientifically useful. If these chemicals are injected into diseased cells, they can detect changes in cells that can be used to study diseases like cancer and muscular dystrophy. Moreover, electronic detectors built with luciferase and luciferin have been fitted into spacecraft. It is to detect life in outer space and food spoilage and bacterial contamination on earth.

Firefly lights are the world’s most efficient lights. While incandescent bulb emits 10% of its energy as light and the rest as heat, a fluorescent bulb emits 90% of its energy as light, and fireflies give out 100% of its energy as light. Firefly light is also called “cold light” as it generates no heat.

Fireflies are carnivorous. Their larvae usually eat snails and worms. Some fireflies, like the genus photuris, are known to eat other fireflies. Photuris imitates female flashes of photinus to attract the males of that species. But it turns out that a flashing photuris is not motivated by romance, but with a desire to devour the male fireflies lured by the flashing signal.

Sometimes male photuris mimics male photinus to attract females of their species. A female shows up looking for food but gets a mate instead. Even more fascinating, scientists believe some photinus males mimic female photuris, sending out bad impressions of photinus male flashes to scare off other photinus males, thus reducing competition.

Fireflies, however, don’t live that long. Their adults live long enough to mate and lay eggs. The larvae usually live for about one to two years, from the mating season before becoming adults and giving birth to the next generation of lightning bugs.