Huitzilopochtli's name is a combination of two Nahuatl (or Aztecan) words, huitzilin, meaning hummingbird, and opochtli, which means left — the god's name translates literally as "Hummingbird on the Left." This resulted in Huitzilopochtli often being depicted as a blue- or green-colored hummingbird or as a warrior whose armor and helmet were made of hummingbird features. But Aztecs also believed dead warriors were reincarnated as hummingbirds and they called the south the left side of the world. So, translated another way, Huitzilopochtli's name means "Resuscitated Warrior of the South." The Aztecs believed their sun god, who was said to be in constant struggle with darkness, required blood from a human heart as nourishment to ensure his survival. To feed their god, the people of the sun offered up their own in the form of human sacrifice.