Tribes also differ greatly from each other. There are also spirits which control the weather, spirits which interact with humans, and others who inhabit the underworld. Simultaneously the Creator and the spirits may be perceived as a single spiritual force, as in the unity called Wakan-Tanka by the Lakota and Dakota. One set of themes found in some tribes describes that in the beginning, the world was populated by many people. Most were subsequently transformed into animals.
Natives thus feel a close bond with animals because of their shared human ancestry.
Dogs are excluded from this relationship. This bond is shown in the frequent rituals in which animal behavior is simulated. The master of humans is the Creator. The universe is believed to consist of many dark, underground layers through which the humans had to climb. They emerged into the present world through a small hole in the ground - the world's navel.