The intentional consumption of land, mixed with food or not, has been a traditional practice in human societies on all continents, although it seems to have been more common among pregnant women.
Geophagy has occurred among numerous species of mammals, reptiles, and birds, especially herbivores. Thus, it is speculated that certain birds need gravel to harden their beaks or to provide themselves with essential minerals . For example, blue-headed parrots ( Pionus menstruus ), which live in the Amazon, consume a certain type of clay-rich soil to eliminate alkaloids and other toxins present in the fruits on which they feed.
