Many practitioners combine their polytheistic world-view with a pantheistic conception of the natural world as being sacred and imbued with a divine energy force permeating all life. Heathenry is animistic, with practitioners believing in nonhuman spirit persons commonly known as "wights" ("vættir") that inhabit the world, each of whom is believed to have its own personality. Some of these are known as "land spirits" ("landvættir") and inhabit different aspects of the landscape, living alongside humans, whom they can both help and hinder. Others are deemed to be household deities and live within the home, where they can be propitiated with offerings of food. Some Heathens interact with these entities and provide offerings to them more often than they do with the gods and goddesses. Wights are often identified with various creatures from Northwestern European folklore such as elves, dwarves, gnomes, and trolls. Some of these entities—such as the Jötunn of Norse mythology—are deemed to be baleful spirits; within the community it is often deemed taboo to provide offerings to them, however some practitioners still do so. Many Heathens also believe in and respect ancestral spirits, with ancestral veneration representing an important part of their religious practice. For Heathens, relationships with the ancestors are seen as grounding their own sense of identity and giving them strength from the past.