50 Fun Facts About Hedgehog

A hedgehog's spines are hollow hairs stiffened with which protein?

Keratin, the same protein that forms human hair and fingernails, stiffens the hollow spines; unlike porcupine quills, hedgehog spines are not barbed and do not detach easily.

Roughly how many species of hedgehog exist in the wild?

About 17 species, spread across five genera, are recognised; the European hedgehog, Erinaceus europaeus, is the best known and the usual garden visitor in Britain.

Which continent has no native hedgehogs at all?

Australia has no native hedgehogs; the family is native to Europe, Asia and Africa, and there are no living species native to the Americas either. Introduced populations elsewhere tended to become pests.

What does a hedgehog do when it feels threatened?

It rolls into a tight spiny ball: a band of muscle around the body's edge pulls the loose skin shut like a drawstring bag, tucking the face, feet and belly inside.

What is a baby hedgehog called?

A hoglet: litters of around four or five are born blind and deaf in a nest of leaves, and the young begin foraging with their mother at about three to four weeks old.

When a hedgehog meets a strong new smell it chews the source and spreads what over its spines?

Frothy saliva: the hedgehog chews the substance into a foamy spit and licks it over its spines, a habit called self-anointing seen in hoglets as young as 15 days; scent camouflage and toxin defence are the leading theories.

In hibernation, how low can a hedgehog's body temperature fall from its usual 35 °C?

As low as 2-5 °C, barely above freezing: a hibernating hedgehog's body temperature tracks its nest, and its heart slows from about 190 to around 20 beats per minute.

Hedgehogs share distant ancestry with which small mammals?

Shrews: hedgehogs and shrews both belong to the order Eulipotyphla, which also includes moles; porcupines are rodents and only look similar.

How do gymnures, the hedgehog's closest relatives, differ from hedgehogs?

Gymnures, or moonrats, have ordinary fur, no spines; both groups belong to the family Erinaceidae, and the moonrat is known for a powerful smell from its scent glands.

Which old English word for hedgehog survives today as the name of a spiny sea creature?

Sea urchins were once called sea hedgehogs. Hedgepig is another old name for the animal.

How long is the gestation period of the African pygmy hedgehog?

Larger species can take up to 58 days. Litters of the smaller species tend to be bigger, five to six young.

How are a newborn hedgehog's quills arranged at birth so that the mother is not injured?

They are hidden under a fluid-filled skin membrane at birth; within hours the skin dries and shrinks and the quills emerge, and the first soft set is later replaced in a process called quilling.

A protein called erinacin gives hedgehogs some natural immunity to what?

Snake venom: erinacin in hedgehog muscle blocks the haemorrhagic effect of viper venom, and hedgehogs share a mutated nicotinic acetylcholine receptor with pigs, honey badgers and mongooses that resists neurotoxins, so they can eat adders.

In which US state is it illegal to keep a hedgehog as a pet?

California bans hedgehogs as pets under its exotic-animal rules, as do Georgia, Hawaii and Pennsylvania, along with New York City and Washington, D.C.

The African pygmy hedgehog, the usual pet species, is also known by what name describing its hind feet?

Four-toed hedgehog: Atelerix albiventris lacks the hallux, or big toe, on each hind foot, leaving four toes; it became a popular American pet in the 1980s.

To which country did colonists carry hedgehogs from Britain in the 1860s-90s, where they are now pests?

New Zealand: hedgehogs arrived from Britain in the 1870s to remind settlers of home and to control garden pests, and spread so fast that they became a threat to native insects, lizards and ground-nesting birds' eggs.

Which animal is the main predator of hedgehogs in Britain?

The badger: its long claws can prise open a rolled-up hedgehog, and hedgehog numbers are lower where badgers are dense, so hedgehogs tend to avoid areas where the two overlap.

Which fast-food dessert's UK lid was redesigned in 2006 after hedgehogs got their heads stuck?

McDonald's McFlurry: after a British Hedgehog Preservation Society campaign, the UK lid's opening was narrowed in 2006 because hedgehogs drawn in by leftover ice cream could not back out past their spines.

Because hedgehogs are lactose intolerant, the RSPCA says you should never leave out which drink for them?

Milk: hedgehogs cannot digest lactose and it gives them diarrhoea, so the RSPCA advises meaty cat or dog food and a shallow dish of water instead; bread is also discouraged.

A 'Hedgehog Highway' is a square hole cut in a garden fence. How big should it be?

That is about the size of a CD case, big enough for a hedgehog but too small for most pets. Hedgehogs can roam a mile or more a night looking for food and mates.

The British Hedgehog Preservation Society set up Hedgehog Street in 2011 with which other charity?

People's Trust for Endangered Species co-founded Hedgehog Street with the BHPS in 2011; the campaign recruits householders as Hedgehog Champions who link gardens with fence holes and log sightings on the BIG Hedgehog Map.

What job does Beatrix Potter's hedgehog Mrs. Tiggy-Winkle do?

Washerwoman: Mrs. Tiggy-Winkle launders and irons the clothes of the local animals; the 1905 tale drew on Potter's pet hedgehog and Kitty MacDonald, a Scottish washerwoman, and Frederick Ashton danced the role in 1971.

The Tale of Mrs. Tiggy-Winkle is set in which part of England?

The Lake District: the Newlands Valley near Keswick, below Catbells, supplied the backgrounds, and the little girl Lucie was based on Lucie Carr, daughter of the local vicar.

Sonic the Hedgehog made his first playable appearance on the Sega Genesis in which year?

1991: Sonic the Hedgehog launched on the Genesis in North America on 23 June 1991 and in Japan the following month, built as a faster mascot to take on Mario.

Sonic the Hedgehog's signature colour was chosen to match what?

Sega's logo: designer Naoto Ohshima gave Sonic a blue coat to match Sega's cobalt-blue logo, and his first level, Green Hill Zone, became one of gaming's most recognisable settings.

Who voiced Sonic in the 2020 live-action Sonic the Hedgehog film and its sequels?

Ben Schwartz, of Parks and Recreation, voiced Sonic in the 2020 film and its sequels; Jim Carrey played Dr. Robotnik, and fan backlash over Sonic's original design forced a costly redesign before release.

The 'hedgehog' gene, whose mutants sprout spiky bristles, was first discovered in which organism?

Fruit fly: Christiane Nüsslein-Volhard and Eric Wieschaus found hedgehog in 1980 while screening Drosophila for genes that pattern the body; mutant larvae were covered in bristles, and the pair shared the 1995 Nobel Prize.

Besides Sonic, mammals' other two hedgehog genes are named after which kinds of hedgehog?

Desert and Indian hedgehog: the three mammalian genes are Sonic, Desert and Indian hedgehog; Sonic was named by postdoc Robert Riddle after his wife brought home a magazine advertising the video game.

Loss of Sonic hedgehog protein in an embryo can cause which condition, where the forebrain fails to divide?

Holoprosencephaly: without Sonic hedgehog signalling the forebrain fails to split into two hemispheres, and in the severest form, cyclopia, a single central eye develops; the same protein patterns limbs from the zone of polarizing activity.

Which philosopher devised the 'hedgehog's dilemma' of hedgehogs huddling for warmth?

Arthur Schopenhauer set out the parable in his 1851 Parerga and Paralipomena: hedgehogs huddle for warmth but prick each other, so they settle at a middle distance; Freud cited it in 1921.

Isaiah Berlin's 1953 essay contrasts the hedgehog, which knows one big thing, with which animal that knows many?

The fox: Archilochus's fragment 'the fox knows many things, but the hedgehog knows one big thing' gave Berlin his title, and he used it to examine Tolstoy's view of history in War and Peace.

Which 2001 business book by Jim Collins popularised the 'Hedgehog Concept'?

Good to Great, published in 2001, borrowed the idea from Berlin's essay: companies that made the leap focused on the one thing they could be best at rather than chasing many.

In the Queen of Hearts' croquet game, hedgehogs are the balls. What are the mallets?

Soldiers bend over to form the hoops. Alice finds the game maddening because the hedgehogs keep unrolling and wandering off.

The Royal Navy's Second World War weapon nicknamed the 'Hedgehog' was what kind of device?

A forward-throwing anti-submarine mortar: the Hedgehog fired a pattern of 24 contact-fused bombs ahead of the ship, and its rows of empty launcher spigots looked like spines; it sank far more U-boats per attack than depth charges.

A 'Czech hedgehog', seen on Normandy beaches and in Ukraine, is what?

An anti-tank obstacle: three angle-iron beams joined in a star that stops a tank from driving over it; first used on Czechoslovakia's pre-war border fortifications, and in Normandy the Allies cut them up for Sherman hedgerow cutters.

The edible hedgehog mushroom (Hydnum repandum) gets its name from what beneath its cap instead of gills?

Tiny tooth-like spines hang beneath the cap in place of gills, which is why it is also called sweet tooth or wood hedgehog; its firm, nutty flesh makes it a popular edible.

In Yuri Norstein's animated short Hedgehog in the Fog, whom is the hedgehog walking to visit for tea?

A bear cub: the hedgehog sets off with a jar of raspberry jam to visit his friend the bear cub for tea and to count the stars, but wanders into fog and sees a white horse.

Hedgehog in the Fog, voted the best animated film ever by animators in 2003, was made in 1975 in which country?

Soviet Union: Soyuzmultfilm in Moscow produced Yuri Norstein's film in 1975, and in 2003 a poll of 140 animators and critics at Tokyo's Laputa Animation Festival voted it the best animated film of all time.

What is narrator Renée Michel's job in The Elegance of the Hedgehog?

Concierge: Renée Michel is the secretly erudite concierge of a grand Paris apartment building in Muriel Barbery's 2006 novel, played by Josiane Balasko in the 2009 film Le Hérisson.

In Monty Python's 'Piranha Brothers' sketch, what is the giant imaginary hedgehog that terrifies Dinsdale called?

Spiny Norman: the hedgehog's size swells and shrinks with Dinsdale's mood, and at the end of the sketch it turns out to be real, looming over London landmarks bellowing 'Dinsdale!'

Which Roman writer claimed hedgehogs spear fallen apples on their spines for winter?

Pliny the Elder wrote in his Natural History that hedgehogs roll on fallen apples to spear them for winter stores; Isidore of Seville later said the same of grapes, and bestiaries repeated it for centuries.

Rather than curling up, the long-eared hedgehog of Central Asia usually responds to a predator how?

It runs or leaps at the threat: the long-eared hedgehog is far faster than the European species and would rather flee or jump at a predator spines-first than curl up; its ears stick out well beyond its spines.

The desert hedgehog, one of the smallest species, is found in which region?

The Sahara and the Middle East: the desert hedgehog, Paraechinus aethiopicus, ranges across North Africa's deserts and the Arabian Peninsula, hiding in burrows or rock crevices by day and hunting insects, scorpions and small vertebrates at night.

Madagascar's spiny tenrecs mimic hedgehogs but are unrelated. What is this an example of?

Two tenrec species grew hardened spines and learned to curl up independently. Tenrecs are closer to elephants and aardvarks than to hedgehogs.

In Irish folk tradition, a hedgehog leaving its hole on which day was a good-weather omen?

St Brigid's Day, 1 February, the old Irish first day of spring: a hedgehog venturing out was read as a sign of mild weather ahead, the same role the groundhog plays in North America.

Among Bedouins in the Middle East, hedgehog meat is traditionally eaten as a medicine for what?

Rheumatism: Bedouin tradition holds that hedgehog meat treats rheumatism and arthritis; hedgehogs were also eaten in ancient Egypt, and some late-medieval European recipes call for the meat.

According to the RSPCA, roughly how many spines does an adult hedgehog carry?

5,000 to 7,000 spines, each about 2 to 3 cm long and shed and replaced over the animal's lifetime; the spines hide surprisingly long legs, which is why a running hedgehog startles people.

On the 2020 Red List for Britain's Mammals, the hedgehog was classed as what?

Vulnerable: the 2020 Red List for Britain's Mammals, compiled by the Mammal Society, classed the hedgehog as vulnerable to extinction after steep declines in rural populations.

On which Scottish islands did a controversial hedgehog cull begin in 2003 to protect ground-nesting birds?

Outer Hebrides: hedgehogs introduced to the Uists in the 1970s ate the eggs of ground-nesting waders, so Scottish Natural Heritage began culling them in 2003 before switching to trapping and mainland relocation.

In 1981 which UK body ordered a publican to rename his 'Hedgehog Flavoured' snack?

The Office of Fair Trading objected because the snacks contained no actual hedgehog.