In religion we all have a choice to choose what we believe in. The Sioux Indians believed that seven was a special number, that “mother nature” was the biggest spirit, and that everything in nature was special. They believed that not using up everything from an animal or plant was bad luck. This is called Animism and is based on a belief that not only humans have spirits but other things like plants, animals, and rocks also have them too. This also includes things like thunder storms, earthquakes, and rain. Animism is just another reason that the Sioux Indians loved nature.