Dorodango is an art and meditation practice in which mud and water are combined into a sphere and polished to a glossy finish. This incredibly delicate procedure comes from an ancient Japanese tradition, but the word “dorodango” (referring to both the skill and the spheres themselves) resurfaced in the 1990s through the research of Professor Fumio Kayo of the Kyoto University of Education. He was studying experimentation and play in childhood development, and the shiny dirt balls served as the perfect vehicle for his research.