Gross Trivia
0Loading crowd target
0Loading crowd target
6correct to beat the crowd
48 free gross trivia questions with answers. This gross trivia quiz is a tour of the disgusting side of biology and history, all of it true. It starts with you: what lives in your bed, what lives on your face, what earwax is made of and what actually makes a fart smell. Then it moves to the animals that out-gross us: rabbits that eat their own droppings, lizards that squirt blood from their eyes, birds that poop on their legs to cool down, beetles that fire boiling spray, and the whale by-product that ends up in perfume. There is a food section that is not for the squeamish (maggot cheese, fermented shark, civet coffee, birds fermented in a seal) and a history section on Roman toilet sponges, powdered-mummy medicine, the courtier who wiped the king and the summer London's river stank so badly Parliament fled. About forty percent of the questions are easy enough for a family car ride, and none of them is graphic beyond 'eww'. Every answer has been checked against a primary source and shows its citation once you have answered.
30 of 48 questions with answers and explanations. Play the quiz
Q 01What do house dust mites mostly eat?
Flakes of human skin
Flakes of human skin work their way deep into mattresses, pillows and sofas, so that is where the mites gather; most people meet them while asleep in bed.
Q 02House dust mites never bite, so what sets off most dust-mite allergies?
Proteins in their droppings
Proteins in their droppings, mostly leftover digestive enzymes, cause the reaction once breathed in; one national survey found the allergen in the beds of about four in five American homes.
Q 03Demodex mites are eight-legged relatives of spiders that spend their lives where on the human body?
In facial hair follicles
In facial hair follicles, tucked out of sight: researchers could see the mites on only 14% of volunteers, yet DNA tests found them on every adult they checked.
Q 04What is earwax mostly made of?
Shed skin cells
Shed skin cells, rich in the protein keratin, make up most of it; the ear canal's skin creeps outward like a conveyor belt, and chewing or talking helps work the wax out.
Q 05Human earwax comes in which two genetically determined types?
Wet and dry
Wet and dry earwax are set by a single letter of DNA in one gene; the dry version, common in East Asia, also leaves people with far less armpit odour.
Q 06Over 99% of a fart is odourless gas, so what produces most of the smell in the remaining trace?
Sulfur compounds
Sulfur compounds, led by rotten-egg hydrogen sulfide, matched the scores when two judges sniffed samples for a 1998 study; a charcoal-lined cushion then soaked up over 90% of those gases.
Q 07Which medical term names the rumbling of gas moving through your intestines?
Borborygmus
Borborygmus comes from a Greek word coined to imitate the noise itself. The rumble is gas being squeezed along the gut, and it is loudest when there is no food inside to muffle it.
Q 08What compound is the main source of the smell of faeces, yet is used in low doses in perfumes?
Skatole
Skatole takes its name from the Greek for dung, yet at low concentrations it smells floral: it occurs naturally in jasmine and orange blossom, which is why perfumers use it.
Q 09Which waste compound does the liver make from the toxic ammonia left over when the body breaks down protein?
Urea
Urea is the body's safe way to dump spare nitrogen: ammonia would poison the brain if it built up, so the liver converts it and the kidneys flush the result away.
Q 10Because it was essential for cleaning wool, which body fluid was taxed in ancient Rome?
Urine
Urine left to go stale gave launderers the ammonia that cleaned wool. When his son Titus complained about the tax, Emperor Vespasian held a coin to his nose and asked if it smelled.
Q 11The 'sponge on a stick' found in Roman public latrines has traditionally been assumed to be what?
A shared bottom-wiping tool
A shared bottom-wiping tool is the classic reading: Seneca mentions the sponge stick, and latrines kept salt water or vinegar to rinse it. Some scholars now argue it only scrubbed the toilet.
Q 12Which English court official helped the king on the toilet and became hugely powerful as a result?
Groom of the Stool
The Groom of the Stool brought the bowl, water and towels, and the privacy paid off: he became the king's private secretary, kept his personal accounts and decided who got in to see him.
Q 13Which grisly apothecary medicine did European painters also buy as a brown pigment?
Q 21What do rabbits and guinea pigs do with the soft, sticky pellets called cecotropes that they produce?
Eat them
Rabbits and guinea pigs eat them as soon as they appear: microbes in the caecum make B vitamins and protein too far down the gut to be absorbed, so a second trip through is the only way to collect them.
Q 22Hagfish slime swells to what multiple of its volume in under half a second?
10,000 times
10,000 times is the measured figure, as coiled threads unspool and trap seawater. The slime clogs a predator's gills, and the hagfish ties itself in a sliding knot to scrape the goo off its own body.
Q 23Storks and vultures cool down by doing what onto their own legs?
Defecating
Ground-up Egyptian mummies
Ground-up Egyptian mummies were thought to hold healing bitumen. To keep the trade supplied, dealers later passed off the dried bodies of executed criminals as the real thing.
Q 14The "Great Stink" of 1858, when the smell of sewage forced Parliament to act, happened in which city?
London
Joseph Bazalgette's resulting sewer system still serves nine million Londoners today.
Q 15Which famous scientist tested the filth of the Thames in 1855 by dropping pieces of white paper into it?
Michael Faraday
Michael Faraday wetted the scraps so they would sink and dropped some in at every pier; they vanished from sight before sinking an inch. Punch then drew him handing his card to Father Thames.
Q 16The earliest recorded reference to toilet paper, from around 589 AD, comes from which country?
China
China had paper to spare centuries before Europe: the scholar Yan Zhitui wrote that he dared not use sheets bearing the names of sages for toilet purposes, and by the 14th century it was being mass-produced.
Q 17Bed bugs home in on a sleeping person mainly by body warmth and what else?
Carbon dioxide in breath
Carbon dioxide in breath draws bed bugs to a sleeper, along with body warmth. Dirt plays no part, so a spotless bedroom suits them as well as a filthy one.
Q 18Head and body lice are thought to have split at which point in human history?
When humans began wearing clothes
When humans began wearing clothes, some lice moved off the scalp and into the fabric, where body lice live and lay their eggs. Their DNA is now one of the few clues to when people first got dressed.
Q 19Cockroaches have no lungs, so what happens if one loses its head?
It can keep breathing
It can keep breathing because air enters through small holes in each body segment and the brain plays no part. It does not bleed out either, so a headless cockroach can live on for days.
Q 20Some cockroaches can survive on which unlikely food source?
The glue on postage stamps
The glue on postage stamps is a meal to a cockroach, as are soap, toothpaste, hair and book bindings. Being cold-blooded, they can also go about a month with no food at all.
Defecating on their bare legs stands in for sweating, which birds cannot do: the liquid evaporates and carries heat away.
Q 24Turkey vultures find carcasses by smelling which gas given off by early decay?
Ethyl mercaptan
Ethyl mercaptan is the same stink added to odourless fuel gas so people can smell a leak, and oil company engineers noticed turkey vultures gathering wherever a pipeline was leaking it.
Q 25In which muscular organ does an owl press leftover fur and bones into the pellet it coughs up?
Gizzard
The gizzard holds back the fur and bones that stomach acid can't dissolve and squeezes them into a lump of its own shape. Unlike hawks, owls have no crop, so prey drops straight into the stomach.
Q 26Which reptile defends itself by squirting blood from the corners of its eyes?
Horned lizard
The horned lizard eats stinging harvester ants, and a compound from their venom is thought to end up in its blood, which would explain why the squirt tastes foul to dogs, coyotes and wild cats.
Q 27Fulmar chicks defend the nest by spraying attackers with what?
Foul-smelling stomach oil
Foul-smelling stomach oil gave the fulmar its name, from Old Norse words for foul and gull. On a predatory bird it sets and mats the wing feathers, which can leave the attacker unable to fly.
Q 28The Amazon's hoatzin is nicknamed the 'stinkbird' because it does what?
Ferments leaves in its gut like a cow
It ferments leaves in its gut like a cow, the only bird that does, brewing them with bacteria in an oversized crop. The result reeks of fresh manure, and the bulky crop makes it a clumsy flier.
Q 29Wombats are the only animal known to produce droppings of what shape?
Cubes
Cubes take shape in the last stretch of the wombat's gut, where stiff and soft bands of the wall squeeze at different speeds. The physicists who worked it out won an Ig Nobel Prize in 2019.
Q 30Ambergris, a prized perfume fixative, forms in the digestive system of which animal?
Sperm whale
The sperm whale eats squid, and scientists think it coats their sharp beaks in a fatty gut secretion. Fresh, the lump smells faecal; years of sun and salt water turn it sweet and earthy.