Wombats are the only animals on Earth that produce cube-shaped droppings.

In 2018, a research team led by Patricia Yang from the Georgia Institute of Technology uncovered the biological mechanism behind this remarkable phenomenon. They discovered that the final 17 percent of a wombat's intestine has a non-uniform structure, featuring two stiff zones alternating with two flexible zones. These zones apply uneven pressure during the dehydration process, mechanically shaping the waste into flat faces and sharp corners.The study, which won an Ig Nobel Prize in 2019, revealed that the intestinal walls stretch preferentially in specific directions to create the cube shape. This represents a significant evolutionary advantage for the bare-nosed wombat (Vombatus ursinus). These marsupials place their droppings on elevated surfaces like rocks or fallen trees to maximize the reach of their scent signals.If the poop were spherical like that of most other mammals, it would easily roll away from these prominent marking spots. By producing cubes, wombats ensure their territorial markers remain exactly where they are placed, allowing them to communicate with other wombats and avoid unnecessary physical confrontations. Researchers believe this unique digestive process could even inspire new manufacturing techniques for shaping non-spherical soft materials in industrial engineering.