Accessibility Homepage Skip navigation Sitemap

Hedgehog biology

Hedgehogs are an unmistakable mammal. Their spines, along with other features, are well adapted for nocturnal life in the undergrowth. Here we look at what makes a hedgehog a hedgehog…


The west European hedgehog is the UK’s only spiny mammal. An adult hedgehog’s body is around 20-30cm long and covered in sharp spines, each of which is around 2-3cm in length. The spines are made up of keratin; the same material as human hair and nails. Hedgehogs shed their spines over time, with new ones growing in to replace them, just like our hair!

Photo by Hedgehog Champion Angela Danby

An adult hedgehog has between 5,000 and 7,000 spines on it’s body.

A hedgehog’s spines are its main mode of defence against predators. When threatened, the hedgehog will curl up into a tight, spiky ball. The hedgehog has a muscle around it’s body which contracts to allow the hedgehog to curl up, a bit like a draw-string bag. Baby hedgehogs, or hoglets, are born with their spines concealed beneath their skin and shortly after birth, their spines ‘come out’.


Hedgehogs have a short tail, around 2cm long, which is usually hidden beneath their spines.


Hedgehogs have surprisingly long legs; around 10cm in length. These are usually concealed under a hedgehog’s spines, and are only really visible when a hedgehog is running.

Hedgehogs have five-toed, clawed feet enabling them to run, dig and climb as needed.


Hedgehogs have relatively poor eyesight, instead relying on their sense of smell and hearing to navigate and search for prey in the dark.


The UK’s native west European hedgehog has short ears that are largely hidden by fur on the hedgehog’s head.

Photo by Hedgehog Champion Julie Shields.

While UK hedgehogs have small ears, other species in the world have much larger more prominent ears. One notable example is the Long-eared hedgehog, found in Asia and the Middle East, whose ears can be up to 5cm in length!


Most hedgehogs in the UK are brown in colour, but some variation does exist. Hedgehogs can also be blonde (see below) or albino.

Photo by Hedgehog Champion Suzy Weir.

The hedgehog population on the Channel island of Alderney is 25% blonde, as all residents are descended from just a few individuals.