Hedgehog

The hedgehog is a small mammal covered in sharp spines. It lives in parts of Europe, Africa, Asia, and New Zealand, where people brought it long ago. There are 17 different species of hedgehogs. Most adults are about 5 to 12 inches long, or about the length of a pencil. They weigh only a pound or two.

A hedgehog's back is covered with about 5,000 to 7,000 spines. These spines are made of keratin, the same material as your fingernails. They are hollow and stiff, like tiny drinking straws. The belly, face, and legs have soft fur instead. When a hedgehog is scared, it curls into a tight ball. Its spines point out in every direction. This makes it very hard for a fox or an owl to bite.

Hedgehogs come out at night. During the day, they sleep in nests made of leaves and grass under bushes or logs. At night, they wander through gardens, forests, and fields looking for food. They mostly eat insects, slugs, worms, snails, and beetles. They will also eat small frogs, bird eggs, mushrooms, and fruit. A single hedgehog can eat hundreds of bugs in one night, which is why many gardeners are happy to have them around.

Hedgehogs have poor eyesight, but their sense of smell and hearing are excellent. They snuffle along the ground with their pointed noses, sniffing out food hidden in the dirt. They make grunting sounds a lot like a tiny pig, which is how they got their name. "Hedge" is where they hunt, and "hog" is the sound they make.

In places with cold winters, hedgehogs hibernate. They curl up in their nests and sleep for months. Their heart rate drops from about 190 beats a minute to only 20. Their body temperature falls close to the temperature of the air around them. They wake up in spring, thin and very hungry.

Baby hedgehogs are called hoglets. They are born pink and almost blind, with their spines hidden under swollen skin. The spines push through a few hours after birth. This keeps the mother from getting hurt during birth. A litter usually has 4 or 5 hoglets. They stay with their mother for about six weeks before heading off to live alone.

Hedgehogs have one strange habit scientists still do not fully understand. Sometimes a hedgehog finds a strong smell, like a rotting apple or a frog. It chews the object, makes a foamy spit, and spreads the foam all over its spines. This is called self-anointing. Nobody knows exactly why they do it.