Why do humans eat dirt?
Most adults would not be embarrassed to sink their fingers into fertile soil. But young children often use their senses of taste and smell to explore the world, so perhaps for them eating a mouthful of loam is merely curiosity. Children are also more likely to eat soiled food, to eat with dirty hands, and to put things in their mouths. All these behaviours are normal, but they do add up to a surprising amount of soil, more than a gram each day in some children.
