Wombat

The wombat is a stocky, burrowing marsupial from Australia, and the only animal known to science that produces cube-shaped droppings. It makes around eighty to a hundred of them a night, which puts it comfortably ahead of every factory that has ever tried to make a cube out of anything softer than wood.^[1]

The wombat itself is not cube-shaped. Zoologists checked this first, since it would have explained a great deal.

The cubes

For many years nobody could say how the cubes were made. A study published in 2018 found that the walls of the wombat's intestine stretch by different amounts in different places, pressing the contents into flat sides and fairly sharp corners. The work won an Ig Nobel Prize in 2019, the only prize in history awarded for explaining a corner.^[2]

The leading earlier theory, that the wombat's bottom was square, was dropped after someone looked.

Uses

Wombats use their droppings to mark their territory, and like to leave them somewhere prominent, such as on a log or the top of a rock. The flat sides stop them rolling off. Geometers regard this as the only known case of an animal choosing its shape for its stacking properties, and have asked the wombat to consult on shelving.

• Round droppings: roll away; message lost.
• Cube droppings: stay put; message received.
• Triangular droppings: not observed, and not wanted.

Classification

The wombat is classified as a marsupial, a mammal and, informally, the most dependable animal in Australia. Its pouch faces backwards so that soil does not get in while it digs, a design that experts describe as thoughtful and that the joey describes as dark.

See also

• Cube – the shape, before the wombat got to it
• Rock (rock) – where the cubes are left
• Square – a cube that has been flattened

References

1. Burrow, B. (2018). Six Sides: A Natural History. Marsupial Press. p. 6.
2. Committee for Unexplained Corners (2019). “It Was the Intestine”. Annual report.
3. Stack, S. (2004). “Things That Don't Roll Away”. Journal of Shelving 12: 1–4.