Deer are mammals belonging to the Cervidae family. They live in forests, steppes, and mountainous regions throughout much of the Northern Hemisphere. There are more than 50 species of deer worldwide; the most well-known are red deer, roe deer, fallow deer, and reindeer.
The most striking feature of deer is the antlers found on males' heads. These antlers shed and regrow annually. Males generally use their antlers in competition for females and for protection.
