If you’ve ever seen images of Santa Claus’s reindeer, you know that they are always depicted with antlers. After all, the word reindeer means horned animal in Old Norse (a North Germanic language). Unlike most deer, both male and female reindeer grow antlers. Like other deer, reindeer shed their antlers and grow new ones each year. Males use their antlers to attract females and fight off other males. They usually drop their antlers after mating season in November or early December, and grow them back in the warmer months when the sun is out. Female reindeer, on the other hand, keep their antlers until spring. A female uses her antlers during her winter pregnancy to protect her food. Since male reindeer lose their antlers before Christmas, Santa’s reindeer must be female!