What Eats Soil?

Eating Dirt

• It is not clearly understood why animals or people eat dirt, but it is a fact that they do. The types of soils eaten vary widely and can contain either high or low concentrations of vital nutrients. Researchers have found that most soils selected for eating contain higher than normal concentrations of chemicals that bind protective plant poisons.

Soil Provides Grit

• For birds, eating soil is an obvious solution to a pretty serious problem. Because they don't have stomachs like mammals, they need help in efficiently digesting their food. Grit is the answer to this problem. Birds often eat sand and small stones to aid in digestion. As their food churns in muscular pouches, the gritty material helps pulverize it into tiny particles that are digested more efficiently than large hunks would be.

Ruminents and Dirt

• Dirt-eating has long been a problem of livestock raising. Cattle, sheep, goats and horses can kill themselves by eating too much dirt. In the wild, other ruminents, such as elephants and moose, have been observed eating dirt. They are very selective as to which soils they prefer, favoring soil with a high concentration of sodium, calcium, magnesium and potassium. Despite the high concentration of minerals, the animals in question did not appear to be mineral-deficient, and it is hypothesized that this particular combination helps counter acidosis or may detoxify plant compounds.

Human Geophagy

• Significant evidence exists to support the idea that prehistoric and ancient humans ate a variety of clays. Nonindigenous white clays have been found with bones of Homo halibus at an archaeological site in Zambia that dates back over 2.5 million years. This is long before clay crafts became common practice. The Greeks, Romans and even ancient Arabian physicians wrote at length about geophagy. Some were in favor, others were not, but the practice was widespread. Even modern humans eat clay, though many don't realize it. Kaolin clay is a common ingredient in modern antidiarrhea medications.