There is an animal that leaves little cubes behind it.

No, it has not swallowed a box-making machine. It is the wombat, a stocky Australian marsupial that produces remarkably cube-shaped droppings.

For years, the unusual shape puzzled people. How does something formed inside an animal come out looking as though it has been cut into small blocks?

Researchers studying wombats found that the shape develops in the intestine, where different regions of the gut have different levels of stiffness and elasticity. As the material moves through the intestine, those differences help form the edges of the cubes.

Why should a wombat produce cubes at all? One explanation is that the shape helps the droppings stay where they are placed. Wombats use them to mark territory, often leaving them on rocks or other raised surfaces. A rounded object would be more likely to roll away.

It is a wonderfully odd detail about an animal that otherwise looks rather like a small, sturdy bear.

Nature does not always choose the solutions we would expect. Sometimes it produces something so peculiar that scientists have to investigate it before they can explain it.

And somewhere in Australia, a wombat is going about its business without the slightest idea that one of its most unusual habits has become a subject of scientific fascination.

There are days when the world needs no invention from us. It is already strange enough.

Rajat Chandra Sarmah, Guwahati, Assam, India, Instagram @rajatchandrasarmah, YouTube: conversewithasmile, email rajatchandrasarmah@gmail.com