Cube-Shaped Poop

Every so often, nature provides us with a joke that tells itself.

Fruit flies can get drunk. Ducks have corkscrew-shaped penises. Sea cucumbers can expel their internal organs out of their anus to entangle and deter predators.

Wombats, meanwhile, have cube-shaped poop.

That seems … odd.

If you think of a shape an animal might produce with its waste, your mind probably goes in the direction of organic, amorphous shapes, or maybe sphere-like pellets. Circles are organic. Squares, though?

The how is pretty straightforward: wombats have intestines that vary in rigidity. As food moves through their digestive tract, the stiffer areas of the intestines contract faster than the softer areas, so they sort of end up smashing the poop from the sides over and over again, and this inevitably results in something resembling a cube.

The why is maybe less clear, but this is what makes things so interesting. Why did that particular poop architecture survive, so more wombats who made little cube-doodie…