Pica is an abnormal appetite for earth and other non-foods. Pica is common in small children, and occasionally in pregnant women. In extreme forms it is regarded as a medical disorder.

Examples of pica are:

  • geophagy (consumption of soil)
  • mucophagy (consumption of mucus)
  • trichophagia (consumption of hair or wool)
  • scatophagy (consumption of excerement or other filth)
  • please add more examples to this list

Pregnant women have been known to develop strong cravings for soil, chalk, laundry starch, and other non-foods. Some theorize that the women may be craving trace minerals lacking in their system, but there have been no major studies on this.

Warning: pica in children, whilst common, can be dangerous: children eating painted plaster may suffer brain damage from lead poisoning from lead in the paint.