Cubes

Wombat poop:

The wombat, native to Australia, produces about 80 to 100 cubes of poop each night. It is known to deposit piles of dung outside burrows and on top of rocks and logs, most likely to communicate with other wombats, researchers believe.

...But how the wombat produces the cubed shapes is a phenomenon that has puzzled many observers of the furry marsupial.

Researchers, led by the Georgia Institute of Technology's Patricia Yang, said they have uncovered the digestive processes behind the mystery and presented their findings at the 71st Annual Meeting of the American Physical Society's Division of Fluid Dynamics in Atlanta on Sunday.