Fact
Wombats produce cube-shaped droppings
Not moulded on the way out. Shaped by uneven stretching inside the intestine.
Wombat intestines have regions of differing elasticity that compress the contents into flat-sided shapes over the final metres. The cubes do not roll away, which helps the animals mark territory on logs and rocks. The mechanism won an Ig Nobel Prize and has attracted interest from manufacturing researchers.