Kachinas are the essence of the way of Hopi life. They are spiritual beings that are represented by cottonwood root carvings which conform in color, clothing worn and gestures made by that particular Kachina. They can represent birds, animals, plants, human beings and as such, there are hundreds of them. They also play important roles as healers, disciplinarians, comedians, and teachers. Kachinas represented by these carvings are given to girls at certain ceremonies to teach them about the Kachinas. Boys receive other gifts, bows and arrows, rattles, lightning sticks to learn to sing and dance with.
The Kachinas, manifested in physical form, dance during the summer months bringing blessings and rain for the crops to the Hopi people. Each dance us a prayer for the benefit of all mankind requiring reverance on the part of the observer. On Their return to the spirit world in the San Francisco Peaks they take the prayers, offerings, and petitions of the Hopi people as messengers to the Creator.
(http://newsgrist.typepad.com/robertgoldwaterlibrary/images/2008/04/03/kachinas_2.jpg)