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50 free Halloween Science trivia questions with answers — science & nature quiz, new questions added Aug 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 50 questions with answers and explanations. Play the quiz
Q 01Bats are the only mammals capable of what?
True, sustained flight
Flying squirrels only glide. Bats make up about a fifth of all mammal species, with at least 1,500 kinds.
Q 02Roughly what share of all mammal species are bats?
About 20%
They are the second-largest order of mammals after rodents.
Q 03How many bat species feed only on blood?
Three
The common, hairy-legged and white-winged vampire bats, all in Latin America. The 'spectral vampire bat', despite its name, eats other animals.
Q 04What is draculin, found in vampire bat saliva?
An anticoagulant
It stops the victim's blood clotting while the bat laps it up, and it is being studied as a stroke drug.
Q 05How many limbs does a spider have?
Eight
That is what makes them arachnids, not insects. Their body is fused into just two segments.
Q 06Weight for weight, spider silk is stronger than steel but not as strong as what?
Kevlar
Its trick is combining high tensile strength with stretchiness, which is why webs absorb the impact of flying insects.
Q 07How long have spider webs existed, judging from a piece of amber found in Sussex, England?
At least 100 million years
The Early Cretaceous amber preserved silk strands from the age of dinosaurs.
Q 08What are the irritating 'urticating hairs' that many New World tarantulas can flick at attackers?
Barbed setae from the abdomen
They irritate skin and can damage eyes. The goliath birdeater can weigh 170 grams with a 30 cm leg span.
Q 09Botanically, a pumpkin is a cultivated what?
Winter squash
It belongs to the genus Cucurbita and its fruit is technically a berry called a pepo.
Q 10How heavy was the record pumpkin set in October 2023?
About 1,247 kg
That is 2,749 pounds. Ordinary carving pumpkins weigh 3 to 8 kilograms.
Q 11Before pumpkins, what were jack-o'-lanterns carved from in Ireland?
Turnips and mangelwurzels
Irish legend has Stingy Jack roaming the earth with a hollowed turnip for a lamp. Pumpkins took over in America.
Q 12The name jack-o'-lantern originally described which natural phenomenon?
Strange lights flickering over peat bogs
Also known as will-o'-the-wisps or ignis fatuus, 'foolish fire', probably from marsh gas igniting.
Q 13Why do apples float, making apple bobbing possible?
They are less dense than water
Q 21Dry ice, used for spooky fog, is the solid form of which gas?
Carbon dioxide
It has no liquid state at normal pressure, so it goes straight from solid to gas.
Q 22At what temperature does dry ice sublimate at normal atmospheric pressure?
-78.5°C
That is about -109°F. Liquid nitrogen is the one at -196°C.
Q 23What kind of reaction makes a glow stick glow?
Chemiluminescence
Two chemicals mix when you snap the inner vial. It is 'cold light', using no electricity, which is why they are safe near gas.
Firefly light comes from an enzyme acting on a substrate. What is the enzyme called?
The tradition goes back to Roman times, when the first to bite an apple was said to be next to marry.
Q 14What is the scientific term for the excess dark pigment that makes a black cat black?
Melanism
Black leopards and jaguars have the same trait, which helps them hunt at night. In Britain a black cat is good luck.
Q 15In which region is a black cat crossing your path considered good luck rather than bad?
Britain and Ireland
The RSPCA confirmed in 2014 that in UK folklore black cats symbolise good luck. They are still adopted less than other cats.
Q 16Which physiologist first described the 'fight or flight' response, in 1914?
Walter Bradford Cannon
The adrenal medulla floods the body with adrenaline and noradrenaline. It is now often called fight, flight or freeze.
Q 17Which almond-shaped brain structure in the temporal lobes is central to processing fear?
The amygdala
Human screams have a special acoustic 'roughness' that lights it up directly.
Q 18Which acoustic property of human screams selectively activates the brain's danger centre, per Luc Arnal?
Roughness
Roughness is a fast modulation of the sound that the brain treats as an alarm signal.
Q 19What tiny muscles contract to give you goosebumps when you are frightened or cold?
Arrector pili
They pull each hair upright. It is thought to be a vestigial reflex from when our ancestors had fur to fluff up.
Q 20Which organs produce most of the body's adrenaline?
The adrenal glands
They sit on top of the kidneys. A few neurons in the medulla oblongata make some too.
Luciferase
Luciferase oxidises luciferin. Fireflies are actually beetles, and some females fake other species' flashes to eat the males.
Q 25How far can an owl rotate its head?
270 degrees
They have 14 neck vertebrae to our seven, and their eyes are fixed in their sockets, so they have to turn their whole head.
Q 26How many neck vertebrae does an owl have?
14
Their blood vessels are also adapted so the twist does not cut off supply to the brain.
Q 27The 'zombie-ant fungus' Ophiocordyceps unilateralis was discovered in 1859 by which British naturalist?
Alfred Russel Wallace
It hijacks carpenter ants' behaviour before killing them, and inspired the infection in The Last of Us.
Q 28Toxoplasma gondii alters rodent behaviour so they are more likely to be eaten by which animals?
Cats
Cats are the only hosts in which the parasite can reproduce sexually, so making mice careless around cats serves the parasite.
Q 29The 'corpse flower' Amorphophallus titanum smells of rotting flesh in order to attract what?
Carrion beetles and flies
It is native to Sumatra and blooms rarely and briefly, drawing crowds to botanic gardens when it does.
Q 30Chocolate is toxic to dogs because of which compound?
Theobromine
Dark and baking chocolate contain far more than milk chocolate. It has a ten-hour half-life in the body.