geophagy

Eating soil. It is a practice found in many animal species but the reasons for geophagy are poorly understood. Canadian and Japanese researchers established 1996, that chimpanzees eat earth containing clay minerals to combat diarrhoea and other digestive ailments. Other primates are also thought to eat earth for health reasons.

In humans geophagy is usually regarded as a symptom of mental illness but it has also been resorted to during times of extreme hardship. In the 1950s, in China's Hunan province, a light yellowish soil was consumed. According to 1997 research by Canadian nutritionists, the soil is rich in minerals including iron, calcium, potassium, and magnesium. They also looked at the red soil from termite mounds sometimes eaten in Zimbabwe. as a traditional stomach remedy. This was rich in kaolinite, an ingredient commonly used in commercial diarrhoeal preparations.

Parrots eat soil to enable them to cope with the natural defensive toxins produced by plants to thwart seedeaters. The soil binds the quinines and tannins found in seed coating and renders them harmless.