Fireflies
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40 free Fireflies trivia questions with answers — trivia quiz, new questions added Oct 2026.
Few insects are as loved as fireflies. A warm evening, a quiet garden and a scatter of silent sparks is one of summer's oldest shows, and the story behind it is stranger than it looks: a living lamp that barely warms up, flash codes that work like passwords, and a few species that have learned to cheat. This quiz collects the best fun facts about fireflies and lightning bugs. It covers what the insects really are, how the glow is made and what it is for, how they grow up and defend themselves, where to watch thousands flashing in unison, and how they turn up in films, songs, poems and legends from Japan to Italy. It is pitched for curious adults and older children. Most questions can be reasoned out, a handful are for real enthusiasts, and every answer comes with a short explanation you can pass on the next time the garden starts to twinkle.
30 of 40 questions with answers and explanations. Play the quiz
Q 01Fireflies are neither flies nor true bugs; the glowing insects of summer evenings actually belong to which group?
Beetles
Beetles they are: fireflies make up the family Lampyridae, about 2,000 soft-bodied species whose front wings form covers called elytra.
Q 02Female Photuris fireflies copy the flash code of another species so that the males who fly in become what?
A meal
A meal is what the hopeful male becomes: the so-called femme fatale eats him and keeps his defensive toxins for herself. Her own body cannot make those chemicals.
Q 03What nickname do scientists give a firefly's glow because it produces almost no heat?
Cold light
Cold light is the term: a firefly's lantern gives off almost no heat and no infrared, while an old incandescent bulb loses about 90% of its energy as heat.
Q 04Most firefly larvae are hunters that inject digestive fluid into which soft-bodied garden animals?
Snails and slugs
Snails and slugs are the main course, and the victim can be 200 times the weight of a glow-worm larva. The bite slowly paralyses it and turns it to a broth.
Q 05In Disney's The Princess and the Frog, Ray the Cajun firefly is in love with Evangeline, who is really what?
A star
A star is the truth about Evangeline: Ray takes the Evening Star for a lady firefly. Her name nods to a 19th-century poem by Longfellow.
Q 06Crowds gather at Elkmont in the Great Smoky Mountains each year to watch fireflies flash in unison in which state?
Tennessee
Tennessee hosts the show: Photinus carolinus was the first North American firefly found to flash in sync. Males fire a burst of flashes, then all go dark together for eight seconds or more.
Q 07Which US state became the first to adopt a firefly as its official insect, after a campaign by elementary school pupils?
Pennsylvania
Pennsylvania chose the firefly in 1974 after pupils at Highland Park Elementary learned that one species carried the state's name. They wrote letters, ran petitions and handed out bumper stickers.
Q 08Grave of the Fireflies, the animated war film about two orphaned siblings in Kobe, was made by which Japanese company?
Studio Ghibli
Studio Ghibli animated the 1988 film, the first that director Isao Takahata made there. It adapts a semi-autobiographical short story by Akiyuki Nosaka.
Q 09Which electronica act topped the Billboard Hot 100 with Fireflies, a single Adam Young wrote during bouts of insomnia?
Owl City
Owl City is Adam Young's one-man project, and the song recalls the fireflies of his Minnesota hometown, Owatonna. It also reached number one in the UK and Australia.
Q 10What do adult European glow-worms eat during the few summer weeks they spend glowing, mating and laying eggs?
Nothing
Nothing passes their lips, because adult glow-worms have no mouthparts. They run on reserves built up during two or three years as hungry larvae.
Q 11Japan's graduation song Hotaru no Hikari, meaning 'Glow of a Firefly', borrows the tune of which Scottish song?
Auld Lang Syne
Auld Lang Syne supplies the melody, set to new Japanese words in 1881. Shops and restaurants play it at closing time to usher customers out.
Q 12Luciferin and luciferase, the chemicals behind a firefly's glow, take their names from a Latin word meaning what?
Light-bearer
Light-bearer is the meaning of the Latin lucifer, built from lux and ferre, to carry. The two names were coined in the 1880s for the ingredients of living glow.
Q 13The common eastern firefly is nicknamed the big dipper because flashing males swoop in the shape of which letter?
J
Q 21Hygiene swab tests use firefly luciferase because it glows on contact with which molecule that powers living cells?
ATP
ATP makes the firefly chemistry shine, and the glow rises in step with the amount on the swab. Since the molecule is found in and around living cells, a bright result signals microbes.
Q 22In the common European glow-worm, which adults do nearly all the glowing, climbing plant stalks at night to shine?
Wingless females
Wingless females are the glowers: they look like larvae and can be twice the size of the flying males. A male can spot the lamp from up to 45 metres away.
Q 23Fireflies taste foul to birds because they carry lucibufagins, steroids resembling the poison of which animals?
Toads
J is the shape: the male dips, then lights up on the upswing, drawing a glowing hook in the air. The flight path and flash together catch the eye of a partner resting on the plants below.
Q 14Which picture-book author put twinkling lights in the pages of The Very Lonely Firefly?
Eric Carle
Eric Carle liked to give his books an extra dimension: this one twinkles, and The Very Quiet Cricket chirps. His hungry caterpillar has sold tens of millions of copies.
Q 15Which Italian poet compared the flames of Hell's eighth ditch to fireflies seen by a peasant on a summer evening?
Dante Alighieri
Dante Alighieri used the image in Canto XXVI of the Inferno, written in the 14th century. The Italian word he knew the insect by is lucciola.
Q 16Visitors to the Great Smoky Mountains firefly display are asked to cover flashlights with cellophane of which colour?
Red
Red is the rule in the Smokies and at Congaree, because bright white beams can disrupt the flashed messages between fireflies. Even a filtered torch should point at the ground.
Q 17Male common eastern fireflies flash every five to seven seconds, but the gap shortens as which condition rises?
Temperature
Temperature sets the tempo: the warmer the evening, the quicker the flashes come. A watching partner answers each one after a pause of a second or two.
Q 18The common eastern firefly, the most common species in North America, is typically found east of which mountains?
The Rockies
The Rockies mark the western edge of its range. Genetic studies suggest its ancestors started out in Texas and spread north and east from there.
Q 19Luciferin is the compound that a firefly's glow reaction consumes; what kind of molecule is luciferase, which drives it?
An enzyme
An enzyme is what luciferase is, acting on the luciferin. The railroad worm glows in two colours from a single luciferin because it makes two different luciferases.
Q 20The glowworms that light the ceiling of New Zealand's Waitomo caves are the larvae of which kind of insect?
A fungus gnat
A fungus gnat it is: each larva dangles sticky silk threads and glows to lure small flying insects into them. Europe's glow-worm, by contrast, is a true firefly.
Toads of some poisonous species make similar heart-acting steroids, called bufadienolides. The chemicals make fireflies unpalatable to spiders as well.
Q 24Based on genomic analysis, the last common ancestor of all living fireflies is thought to have glowed which colour?
Green
Green is the inferred ancestral glow. The oldest fossils, sealed in amber about 99 million years ago, already have clear lanterns.
Q 25The winter firefly Ellychnia corrusca flies by day and has no lantern as an adult; what does it signal with instead?
Pheromones
Pheromones do the job: scent was the original way fireflies called to each other, before flashing evolved. The larvae still carry two glowing lanterns.
Q 26Female Photinus fireflies judge suitors partly on a protein-rich sperm package that biologists call a nuptial what?
Gift
Gift is the word: the package feeds the eggs she will lay. Suitors that have not mated before offer bigger ones and are chosen more often.
Q 27Every firefly larva glows, so biologists think the insects' light first evolved for which purpose?
Warning predators
Warning predators came first: the glow advertises that a larva tastes bad. Only later was the light co-opted by adults as a courtship signal.
Q 28In a Chinese tale from the Book of Jin, the student Che Yin relied on fireflies in order to do what?
Study after dark
Study after dark was the aim, since he had no other lamp. The image of the industrious student opens a Japanese song heard at graduation ceremonies.
Q 29Visitors to the Smokies' firefly display must stay on the trail because the fireflies replying to the fliers sit where?
On the forest floor
On the forest floor is where the dimmer partners wait, so a step off the path can crush them. They flash their replies during the dark pauses in the display overhead.
Q 30Firefly Aerospace named its Moon lander after which steadily glowing firefly of the southern Appalachians?
Blue ghost
Blue ghost males glow steadily instead of flashing, drifting a few feet above the ground. The lander of that name touched down safely on the Moon in March 2025.