Reindeer are a species of deer that live way up close to the North Pole, where it’s very cold. Reindeer actually go by two different names. In North America, wild reindeer are called CARIBOU. In Northern Europe and Asia, they are called REINDEER. But when caribou become domesticated in North America, that is, kept in herds by people, we call them reindeer again. Some scientists think the reindeer was one of the first domesticated animals - way back around 2000 years ago. Some people who live in the Arctic still depend on reindeer for meat, milk, clothing, and even transportation. You’ve heard of Santa’s sleigh, right? That’s the idea.