Pica is a compulsive eating disorder in which people eat nonfood items. Dirt, clay, and flaking paint are the most common items eaten.
Less common items include glue, hair, cigarette ashes, and feces. The disorder is more common in children, affecting 10% to 30% of young children ages 1 to 6.
It can also occur in children and adults with intellectual and developmental disabilities, such as autism. On rare occasions, pregnant women crave strange, nonfood items. For these women, pica often involves eating dirt and may be related to an iron and zinc deficiency.