Hedgehogs are a group of Old World spiny mammals. When they feel threatened, they roll into a tight ball with the spines sticking out. However, the spines aren't barbed like the quills of a porcupine, and the hedgehog "ball" appears cute or humorous to human eyes. Naturally curious, hedgehogs often become tame and seem to enjoy being handled by their owners.

Unfortunately, there's a dark side to hedgehogs. They were introduced to New Zealand, where they became a serious invasive species, perhaps because local predators don't know what to make of them. Many places, including Australia, some American states, and even some Canadian city governments ban or restrict hedgehogs. Check your local laws before you purchase a pet you might not be allowed to keep.