Kachinas are spirits or personifications of things in the real world. These spirits are believed to visit the Pueblo villages during the first half of the year. A kachina can represent anything in the natural world or cosmos, from a revered ancestor to an element, a location, a quality, a natural phenomenon, or a concept. There are more than 400 different kachinas in Hopi, Zuni and Pueblo culture. The local pantheon of kachinas varies in each pueblo community; there may be kachinas for the sun, stars, thunderstorms, wind, corn, insects, and many other concepts. Kachinas are understood as having humanlike relationships; they may have uncles, sisters, and grandmothers, and may marry and have children. Although not worshipped, each is viewed as a powerful being who, if given veneration and respect, can use his particular power for human good, bringing rainfall, healing, fertility, or protection, for example. One observer has written: The central theme of the kachina (religion) is the presence of life in all objects that fill the universe. Everything has an essence or a life force, and humans must interact with these or fail to survive.