What do you think of this fact?
Picture yourself walking through the Australian bush at night and tripping over small, perfectly edged cubes. Not rocks. Not toys. Wombat poop.
How on earth does that work?
For a long time people assumed wombats must have a square-shaped exit. They don’t. A team led by researcher Patricia Yang took a closer look (yes, that was actually her job) and found that the cubes are shaped inside the intestine.
A wombat’s gut isn’t equally stretchy everywhere. Some sections are stiffer, others more elastic. As the poop slowly moves through the last stretch of intestine, those uneven walls squeeze it into shape until edges and corners form. On top of that, wombats pull a huge amount of water out of their food, so the poop ends up dry enough to keep its shape.
The discovery won an Ig Nobel Prize in 2019, the award for research that first makes you laugh and then makes you think.
But why?
Wombats use their cubes to mark territory, often on rocks or logs. The theory: cubes don’t roll away. A round pellet on a boulder would be gone with the next gust of wind, while a cube stays put and tells every other wombat: I live here.
A single wombat drops 80 to 100 cubes a night. Sometimes nature is just more efficient than any factory.
What engineers want to learn from it
Making cubes in industry takes molds, presses or cutting tools. The wombat does it with a soft tube. The researchers think this principle might one day help manufacture soft materials.
So if anyone asks what you learned today, you have your answer.