Now, scientists in the US may have discovered how and why the phenomenon occurs.
Dr Patricia Yang, a fluid hydrodynamics specialist from Georgia Institute of Technology, has a particular interest in studying how blood, food and urine move within animals’ bodies.
She and her colleagues found that wombats’ digestive processes and soft tissue structures produce the unusual shape.
”The first thing that drove me to this is that I have never seen anything this weird in biology. That was a mystery,” said Dr Yang.