Clearing evil or decay, or taking in good, is symbolized as devouring it – that is, eating it greedily. Kali, the hindu mother goddess, as the keeper of the graveyard, demonstrates this, as do the devouring gods such as dionysus.
Such clearing is a way of returning to source and receiving spiritual upliftment.
Shamanic belief puts forward the theory that we take on the power of that which we eat. We are not allowed to eat our own totem animal, however.