10 Interesting Facts About Hedgehogs

Hedgehogs live wild across Europe, the Middle East, Africa, and Central Asia, and a European hedgehog has around 5,000 spines. These ten facts come from Hedgehog Street, the Animal Diversity Web at the University of Michigan, the Merck Veterinary Manual, and two research papers. Most of them are about the European hedgehog (Erinaceus europaeus), the wild hedgehog of Europe. The hedgehog kept as a pet is a different species, the four-toed or African pygmy hedgehog.

1. Hedgehogs Live Across Europe, The Middle East, Africa, And Central Asia

Hedgehog Street says hedgehogs “live across Europe, the Middle East, Africa and Central Asia.” The Hedgehog Street page linked here as 17 species of hedgehog says: “There are 19 species in five genera of hedgehogs worldwide: Erinaceus, Paraechinus, Mesechinus, Atelerix and Hemiechinus.”

The Animal Diversity Web says the European hedgehog is “commonly found across Europe and into central Asia.” It is also found in New Zealand, “where they were introduced in the late 1800s.” The Merck Veterinary Manual says hedgehogs are “native to dry, open habitats in central and eastern Africa,” in its section on four-toed (African pygmy) hedgehogs.

2. A European Hedgehog Has Around 5,000 Spines

The Animal Diversity Web says “An adult hedgehog usually has around 5,000 spines covering its body.” Hedgehog Street, writing about the west European hedgehog, says an adult has “between 5,000 and 7,000 spines.” Read more about four to seven thousand spines.

The Animal Diversity Web says “Spines are made of keratin and are attached to the skin in a similar way to hair.” Hedgehog Street says “Hedgehogs shed their spines over time, with new ones growing in to replace them.”

3. A Hedgehog Curls Into A Ball When Threatened

The Animal Diversity Web says “When threatened, hedgehogs curl into a ball, exposing their sharp spines while protecting their vulnerable underbelly and face.” It says a “sheet of muscle that covers its back” lets all of the spines be erected at once when a hedgehog rolls into a ball.

The same page lists dogs, foxes, snakes, large owls, and badgers as predators of the European hedgehog. It adds that “Some predators, such as badgers and foxes, may be able to gain access to the hedgehog by wedging their noses into the crease where the top and bottom of the spiny coat meet.” For the four-toed hedgehog, the Merck Veterinary Manual says “A wary hedgehog will erect the spines and crouch.”

4. Hedgehogs Are Active At Night

European hedgehogs are primarily active at night. The Animal Diversity Web says the species is “nocturnal, predominantly solitary, and non-territorial,” and that it rests during the day in shallow nests made of “twigs, leaves, grass, pine needles, and other foliage.” The Merck Veterinary Manual calls four-toed hedgehogs “solitary, nocturnal mammals.”

5. Hedgehogs Find Their Way By Smell And Hearing

Hedgehog Street says “Hedgehogs have relatively poor eyesight, instead relying on their sense of smell and hearing to navigate and search for prey in the dark.” The Animal Diversity Web says the mechanisms of hearing in the European hedgehog “have not been well studied,” and that research on a related species, the long-eared hedgehog, “has found it capable of processing high-frequency sounds up to 45kHz.”

For four-toed hedgehogs, the Merck Veterinary Manual says “Although they have sensitive olfaction and hearing, their eyesight is poor.”

6. European Hedgehogs Mostly Eat Invertebrates

Hedgehog Street, writing about the west European hedgehog, says “The majority of their diet is made up of invertebrates (or creepy crawlies).” It lists “worms, beetles, slugs, caterpillars, earwigs and millipedes” as the most important ones, and says that “More infrequently, they will take advantage of carrion, frogs, baby rodents, baby birds, birds’ eggs and fallen fruit.”

Hedgehog Street also covers two old beliefs. People once thought hedgehogs sucked milk from cows. It says “Milk also makes hedgehogs ill as they are lactose intolerant, so it is important to only ever leave them water to drink.” Medieval people believed hedgehogs carried fruit on their spines, and Hedgehog Street says this “myth is almost certainly untrue.”

7. European Hedgehogs Hibernate In Winter

Hedgehog Street, writing about the west European hedgehog, says “Hedgehogs usually hibernate from October/November through to March/April” and that during hibernation they “drop their body temperature to match their surroundings and enter a state of torpor.” It says “Any disturbance during this period can be extremely dangerous, as hedgehogs use up their precious energy reserves in order to become active again.”

The Animal Diversity Web’s European hedgehog account says “In colder areas, hibernation usually begins in October and lasts until April; in warmer areas, hedgehogs may only hibernate during the coldest of winters.” It says the breaks in hibernation “occur every 1 to 2 weeks and last for 1 to 2 days, during which hedgehogs forage for food and urinate.”

8. Hedgehogs Cover Their Spines In Frothy Saliva

The Merck Veterinary Manual describes how a four-toed hedgehog does it: “In self-anointing, the hedgehog licks, bites, or holds the novel material in its mouth, creates a frothy saliva, and applies the saliva mixture to its spines with its long tongue.”

Robert Brockie wrote a 1976 paper in Animal Behaviour on self-anointing by wild European hedgehogs in New Zealand. Of 929 wild hedgehogs he examined, “nineteen bore signs of recent self-anointing.” Among adults, he found it “was confined to the breeding season,” and he wrote that “self-anointing may serve as a form of sexual signal.” In captivity, “the self-anointing reflex is triggered by novel objects or odours.”

9. European Hedgehogs Have Partial Resistance To Snake Venom

Hedgehog Street, writing about the west European hedgehog, says “Research shows hedgehogs have a partial resistance to snake venom.” It adds that “a bite to the face or leg would still make a hedgehog very ill, and could even kill it.” It also says “The only venomous snake in Britain is the adder, which is incapable of biting a hedgehog through its spines.”

A 1996 paper in Toxicon by Mebs and colleagues purified a protein called erinacin from the skeletal muscle extract of the European hedgehog. The abstract says the protein “effectively inhibited the activity of Bothrops jararaca venom haemorrhagin.”

10. Hedgehogs And Porcupines Are Different Animals

The Animal Diversity Web lists the European hedgehog in the order Erinaceomorpha, “gymnures and hedgehogs,” and the North American porcupine in the order Rodentia, “rodents.” The European hedgehog’s coat “consists of 3/4 to 1 inch spines.” The North American porcupine has “approximately 30,000 quills” that are “usually around 75 mm long and 2 mm wide,” with “microscopic barbs on the tip.”

Hedgehog Street says the west European hedgehog’s body is “around 20-30cm long.” The Animal Diversity Web says North American porcupines “range in length from 600 to 900 mm.” It calls porcupines “generalist herbivores.”

FAQs

How many babies do hedgehogs have?

Hedgehog Street says baby hedgehogs are called hoglets and that “The average litter size is four or five young, though can be as many as seven.” It adds that they “usually only wean two or three successfully.” The Animal Diversity Web says European hedgehog females give birth to “four to six offspring per litter” and that after birth “the fluid is absorbed and the spines are revealed” within 24 hours.

How long do hedgehogs live?

The Animal Diversity Web says “In the wild, European hedgehogs can live up to six years. In captivity, they can live as many as ten years.” The Merck Veterinary Manual lists an average lifespan of 4 to 6 years for four-toed hedgehogs.

Can you keep a hedgehog as a pet?

The Merck Veterinary Manual says “Four-toed hedgehogs are often kept as pets. Some US states and municipalities require a permit to keep a hedgehog as a pet, whereas in other parts of the US, having a pet hedgehog is illegal.” It also says “Wild four-toed hedgehogs are solitary; as pets, they are usually housed in individual cages.” Read more about introducing them to other pets.

What should I do if I find a hedgehog in daylight?

Hedgehog Street says “If you spot a hedgehog at night and it looks healthy then the best thing you can do is leave it alone,” because “Hedgehogs are wild animals and so can get very easily stressed by human contact.” It says a daytime sighting “could be a warning sign that all is not well,” and that “if you find a hedgehog staggering around, lying still (not in a nest), with flies around it or obviously sick or injured be it day or night, it needs urgent help.” The British Hedgehog Preservation Society lists its hedgehog first aid advice for a hedgehog that is “lethargic, lying out in the open, has flies around it, is wobbly, injured, trapped or gives you any other cause for concern.”

Are hedgehogs good for gardens?

Hedgehog Street says “Hedgehogs are widely recognised as a potent ally in the garden” and that “Gardens provide hedgehogs with a plentiful supply of food, both natural and supplementary, as well as many potential nest sites for breeding, resting and hibernation.” It also says “In general any chemical treatment that kills slugs, snails or insects will be bad for hedgehogs and should be avoided.” The Animal Diversity Web says hedgehogs “may help control insect pest populations in some areas.”

Sources

• Hedgehog Street. History of the hedgehog.
• Hedgehog Street. Hedgehog biology.
• Hedgehog Street. What do wild hedgehogs eat?
• Hedgehog Street. Hedgehog hibernation.
• Hedgehog Street. Hedgehog breeding and babies.
• Hedgehog Street. Where do hedgehogs live?
• Hedgehog Street. Sick or injured hedgehog?
• Hedgehog Street. Slug pellets.
• British Hedgehog Preservation Society. Found a hedgehog? Hedgehog First Aid Advice.
• Animal Diversity Web, University of Michigan Museum of Zoology. Erinaceus europaeus (western European hedgehog).
• Animal Diversity Web, University of Michigan Museum of Zoology. Erethizon dorsatum (North American porcupine).
• Merck Veterinary Manual. Overview of Four-Toed (African Pygmy) Hedgehogs.
• Merck Veterinary Manual. Management of Four-Toed (African Pygmy) Hedgehogs.
• Brockie, R. “Self-anointing by wild hedgehogs, Erinaceus europaeus, in New Zealand.” Animal Behaviour, 1976. sciencedirect.com.
• Mebs, D., Omori-Satoh, T., Yamakawa, Y., and Nagaoka, Y. “Erinacin, an antihaemorrhagic factor from the European hedgehog, Erinaceus europaeus.” Toxicon, 1996. pubmed.ncbi.nlm.nih.gov.

Your Animal Hearted purchase saves lives! 25% of all proceeds are donated to no-kill animal shelters!