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:
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.