Eating dirt to get minerals out of it if there's nothing else available.

Geophagy is the term for the form of pica in which the patient eats dirt.

To show us the world's features, like mountains, valleys, and other natural resources.

It helps us 'spot' the world at an angle that is easy to study.

There are obvious risks in the consumption of earth that is contaminated by animal or human feces; in particular, parasite eggs, such as roundworm, that can stay dormant for years, can present a problem. Tetanus poses a further risk. Nevertheless, these risks are generally well understood by most tribal populations that engage in geophagy, hence 'clean' earth from below the surface level is sought out. Children's predilection to engage in geophagy makes them more susceptible to worm infestations. Other dangers associated with geophagia include damage to tooth enamel, the ingestion of a variety of bacteria, various forms of soil contamination, and intestinal obstruction.

In the traditional societies, there is a widespread practice to heat-treat (bake) the earth before consumption, and this tends to mitigate the risks to some extent.

There is a psychological hypothesis, which is centred on the cravings reported by clay eaters. Researchers' attention was directed mainly towards pregnant and postpartum women and their emotional states. Geophagy was attributed to feelings of misery, homesickness, depression, and alienation