Cute Hedgehog

The hedgehog's back is made up of two large muscles, which control the positioning of its quills. There are about 5,000 to 7,000 quills on the average hedgehog, and these are durable on the outside, while being filled with air pockets on the inside. The hedgehog uses its quills to protect itself from predators, using muscles which draw their quilled skin to cover their full body, and pulling in the parts of their bodies not covered, such as their head, feet, and belly. This form of defense is the hedgehog's most successful, but is usually their last resort.
Hedgehogs have many alternate defense mechanisms. In most situations a hedgehog will flee rather than confront a threat, rolled up in a ball or not. All hedgehogs possess the stamina to run, many can make 4.5 miles per hour or better, and are particularly adept at climbing steep walls, trees, and fences and even swimming.