Halloween Science Trivia
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47 free Halloween Science trivia questions with answers — science & nature quiz, new questions added Oct 2026.
40 free Halloween Science trivia questions with answers. Everything spooky has a scientific explanation, and this quiz collects the best of them. It covers bats (the only flying mammals) and the anticoagulant in vampire-bat spit named after Dracula, spider silk that outperforms steel, why pumpkins are berries and how heavy a record one gets, why apples float for bobbing, black cats and melanism, what adrenaline and the amygdala do when you get scared, why you get goosebumps, dry-ice fog and glow-stick chemistry, owls that turn their heads 270 degrees, the fungus that turns ants into zombies, the corpse flower, chocolate and dogs, how many bones you have, rigor mortis and the five stages of decomposition, and whether the full moon really changes behaviour. Easy questions ask which are the only mammals that fly and what dry ice is made of; the hard ones want the enzyme behind firefly light, the naturalist who found the zombie-ant fungus and the temperature at which dry ice sublimes. Written for science teachers wanting a Halloween lesson, families, and pub-quiz teams in October. Every answer was checked against Wikipedia's articles on the animals, plants, chemistry and biology involved, and each question carries the sentence that backs it up.
30 of 47 questions with answers and explanations. Play the quiz
Q 01Bats are the only mammals capable of what?
Powered flight
Powered flight is the bats' alone: flying squirrels, despite the name, can only glide from tree to tree, while a bat flaps a wing built from its own hand, with skin stretched between long fingers.
Q 02Bats are the second-largest order of mammals, with more than 1,400 species, behind only which group?
Rodents
Rodents make up about 40% of all mammal species and bats about another 20%, so more than half of the world's mammals are one or the other.
Q 03Of more than 1,400 bat species, how many feed only on blood?
Three
Three: the common, hairy-legged and white-winged vampire bats, all in Latin America. A vampire that fails to feed can beg from a roost-mate, which brings up part of its own blood meal to keep it alive.
Q 04What is draculin, found in vampire bat saliva?
An anticoagulant
An anticoagulant: draculin blocks two of the blood's clotting factors, so the small bite keeps flowing while the bat laps up its meal.
Q 05Spiders, scorpions and ticks all belong to which class of animals?
Arachnids
Arachnids. A spider straightens its legs not with muscle but by pumping fluid into them like a hydraulic ram, which is why the legs fold inward when the pressure goes.
Q 06Weight for weight, spider silk is stronger than steel but weaker than which material?
Kevlar
Kevlar is stronger still, but it is stiff where silk stretches, so a web can soak up the energy of a flying insect without snapping.
Q 07Spider web threads found in amber from Sussex, England, date from the age of which animals?
Dinosaurs
Dinosaurs: the amber is about 140 million years old, and its threads already carry sticky droplets, so spiders were gluing down their prey the way garden orb weavers do today.
Q 08Many New World tarantulas defend themselves by kicking what off their abdomens at an attacker?
Barbed hairs
Barbed hairs: the barbs let a bristle work its way into skin and eyes, and doctors have had to remove them surgically from the eyes of people handling pet tarantulas.
Q 09A pumpkin is a cultivated variety of which kind of plant?
Winter squash
Winter squash is picked fully ripe, once the rind has hardened, which is why a pumpkin will keep through the winter while a summer squash such as a courgette is eaten young and tender.
Q 10How heavy was the pumpkin that set a world record in October 2023?
About 1,250 kg
About 1,250 kg: Travis Gienger's pumpkin weighed 1,246.9 kg. It held the record until 2025, when English twins who had been growing giants for 50 years beat it by 32 kg.
Q 11Before pumpkins, what were jack-o'-lanterns carved from in Ireland?
Turnips and mangelwurzels
Turnips and mangelwurzels were hollowed out as lanterns, and Irish legend has Stingy Jack roaming the earth with a coal in a carved turnip. Immigrants to America switched to the native pumpkin.
Q 12The name jack-o'-lantern once described which natural phenomenon?
Strange lights flickering over peat bogs
Strange lights flickering over peat bogs were pictured as a man carrying a lamp, 'Jack with the lantern', who was said to lead night travellers astray. The name reached carved pumpkins only in the 1800s.
Q 13Which pigment gives a pumpkin its orange colour and is turned into vitamin A by the body?
Q 21Dry ice turns straight from a solid into a gas, a change known as what?
Sublimation
Sublimation happens at -78.5°C in dry ice, cold enough to burn bare skin like frostbite, which is why it is handled with insulated gloves.
Q 22What kind of reaction makes a glow stick glow?
Chemiluminescence
Chemiluminescence turns a reaction's energy straight into light with almost no heat, which is why a glow stick stays cool in the hand: the same cold glow lights a firefly.
Q 23Which enzyme makes a firefly's tail light up?
Luciferase
Luciferase makes the light by oxidising a compound called luciferin. Female Photuris fireflies copy another species' flash code to lure in its males, then eat them.
Beta-carotene
Beta-carotene also colours carrots and sweet potatoes, and eating a great deal of them can tint your palms and soles orange-yellow, a harmless effect that fades when you cut back.
Q 14What is the scientific term for the excess dark pigment that makes a black cat black?
Melanism
Melanism also makes the 'black panther', which is no species of its own, just a black leopard or jaguar. The trait has arisen separately in cats: one mutation blackens a house cat, a different one a jaguar.
Q 15Which American physiologist first described the 'fight or flight' response?
Walter Cannon
Walter Cannon was X-raying animals' stomachs to watch digestion when he noticed the movements stopped whenever the animal was upset, and he followed that clue to the body's emergency response.
Q 16Which almond-shaped brain structure in the temporal lobes is central to processing fear?
The amygdala
The amygdala was destroyed by a rare disease in an American woman known as S.M. Researchers who walked her through a haunted house and showed her horror films found they could not frighten her.
Q 17Rather than pitch or volume, which sound quality, a rapid flutter in loudness, did a 2015 study find makes screams alarming?
Roughness
Roughness, loudness that flickers 30 to 150 times a second, sets a scream apart from speech and is also built into artificial alarms; it engages the brain structures that size up danger.
Q 18Goosebumps form when a tiny muscle tightens at the base of each what?
Hair
Hair: each one has its own muscle, the arrector pili, that pulls it upright. In our furry ancestors that trapped warm air or made a frightened animal look bigger; on bare skin it leaves only bumps.
Q 19The glands that make adrenaline sit on top of which organs?
The kidneys
The kidneys: 'adrenal' comes from the Latin for 'near the kidney', and each of the two small glands sits like a cap on top of one.
Q 20Dry ice, used for spooky fog, is the solid form of which gas?
Carbon dioxide
Carbon dioxide never melts at everyday pressure: the solid turns straight into gas. Dropped in water, it throws up white 'smoke' that is really a fog of tiny water droplets, chilled so that it hugs the floor instead of rising.
Q 24Owls turn their heads so far because they cannot do what?
Move their eyes
Move their eyes: an owl's eyes are tubes held fast in the skull, so the whole head turns instead, up to 270 degrees each way, and holes in the neck bones ten times wider than the artery inside keep blood flowing.
Q 25An owl has 14 neck bones, twice as many as which animal?
Giraffe
The giraffe has only seven neck bones, the same number as a human: each one is simply stretched, to more than 25 cm.
Q 26Which video game and TV series took its brain-hijacking infection from the real 'zombie-ant fungus'?
The Last of Us
The Last of Us imagines the fungus jumping to people. In real carpenter ants it drives the insect down from its nest to clamp its jaws on a leaf vein and die, and a stalk then sprouts from its head to shed spores.
Q 27Toxoplasma gondii changes the behaviour of infected mice and rats so they are more likely to be eaten by which animals?
Cats
Cats are the only animals in which the parasite can reproduce sexually, so it rewires infected mice and rats to be drawn to the smell of cat urine instead of fleeing it.
Q 28The 'corpse flower' Amorphophallus titanum smells of rotting flesh in order to attract what?
Carrion beetles and flies
Carrion beetles and flies come looking for a carcass to lay their eggs in and carry off pollen instead. The bloom even heats itself to about 36°C, in pulses, to drive the stench further.
Q 29Chocolate is toxic to dogs because of which compound?
Theobromine
Theobromine lingers in a dog, which needs about 17.5 hours to clear half a dose, so the stimulant builds up to a poisonous level. Dark and baking chocolate carry the most.
Q 30How many bones are in an adult human skeleton?
206
206 is what is left after years of fusing: a baby is born with dozens more bones, and pieces such as the five vertebrae at the base of the spine knit into one as the body grows.