Geophagia has been around for centuries. In the 18th century, Roman physicians reported on the effects of eating dirt. Scholars have studied the act of eating dirt in contemporary urban South Africa.

Most people sweep dirt into the trash, but a grassroots social media trend suggests sprinkling it on your lunch as a healthy treat. Health experts, however, say the risks of injury and disease far ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...