 Her skin became grasses and small flowers, her hair the trees and herbs, her eyes the springs and wells, her nose the hills and valleys, her shoulders the mountains, and her mouth the caves and rivers.Since Tlaltecuhtli's body was transformed into the geographical features, the Mexica attributed strange sounds from the earth as either the screams of Tlaltecuhtli in her dismembered agony, or her calls for human blood to feed her.As a source of life, it was thought necessary to appease Tlaltecuhtli with blood sacrifices, especially human hearts.