A zebra is a wild horse with distinctive black and white stripes covering its entire body. Zebras live in the grasslands and savannas of Africa, where they graze on grass and travel in herds for protection against lions, hyenas, and other predators.

Each zebra's stripe pattern is unique, like a fingerprint. Scientists still debate exactly why zebras have stripes: the patterns might confuse predators when the herd runs together, help zebras recognize each other, or even discourage biting flies. Whatever the reason, those bold stripes make zebras one of the most recognizable animals on Earth.

There are three species of zebras, with the plains zebra being the most common. Unlike horses, zebras have never been successfully domesticated. They're more aggressive and unpredictable than horses, and they have a powerful bite they're not afraid to use. Early settlers in Africa tried repeatedly to tame zebras for riding and farm work, but zebras refused to cooperate.

People sometimes use zebra to describe anything with black and white stripes, like a zebra crossing (the striped crosswalk where pedestrians cross streets). In medical training, doctors learn that when diagnosing patients, they should think of common diseases first: “When you hear hoofbeats, think horses, not zebras.”