Researchers discover how wombats excrete poo cubes

An international team of scientists has been able to mimic how a wombat produces square poo – and it could change the way geometric products are manufactured in the future.

Research published today in the Journal of the Royal Society of Chemistry Soft matter, goes on to discover that wombat poo forms its characteristic shape in the intestines of the wombat, not at the point of exit as previously thought.

They have now found that the slow passage of the stool and the varying stiffness in the last 17 percent of the intestines produce the square shape – before exiting through the round anus.

Not only does this discovery apply to wombats – cancer, for example, increases tension in various parts of the colon and can produce different shaped feces – but the technique could help scientists and engineers develop new ways to produce soft materials, such as plastic in geometric shapes. form.

These lessons can also be applied to other areas such as clinical pathology and digestion in other species, including humans.

University of Tasmania wildlife ecologist Dr. Scott Carver made the accidental discovery while dissecting a wombat cadaver as part of his primary research into the treatment of scabies disease in wombats.

The cube poo study focuses on bare-nosed (common) wombats, which are mainly found in southeastern Australia.

“Bare-nosed wombats are known for producing distinctive, cube-shaped cats. This ability to form relatively uniform, clean-cut feces is unique in the animal kingdom,” said Dr. Carver.

“They place these feces at prominent points in their home, such as around a rock or a tree trunk, to communicate with each other. Our research found that these cubes form in the last parts of the gut – ultimately proving that you really fit. a square pin through a round hole. “

Using a combination of lab tests and mathematical models, the researchers found that there are two rigid and two more flexible areas around the perimeter of the wombat gut.

Professor David Hu of the Georgia Institute of Technology said, “Coming up with this absolutely new mechanism for how to shape these angles with a knife or sharp edges has taken many iterations and has now been accomplished without using the wombat itself.”

The combination of dryness of the stool in the distal colon and muscle contractions forms the normal size and angles of the stool.

Wombat intestines are about 10 feet long, ten times the length of a typical wombat’s body.

When people eat, food products travel through the intestines within a few days. A wombat’s digestive process takes up to four times as long so that it can extract all possible nutrients. They are also more efficient at extracting water from the gut, with their stools a third drier than humans.

The results can be used to inform the wombat’s digestion in captive management.

“Cubing can help us understand the hydration status of wombats, as their stools may appear less cubed in wetter conditions. It also shows how stiffening can produce smooth sides as a hallmark of pathology,” said Dr. Carver.

“Now we understand how these cubes are formed, but there is still much to learn about the behavior of wombats to fully understand why they evolved to produce cubes in the first place.”

Patricia Yang, a postdoctoral researcher at Georgia Tech, added that the research could have several applications. “For example, we know that one of the early symptoms of colon cancer is that part of the colon can become stiff. It is then possible that this may form a rim or unusual shape in the stool and be an early indicator of the health of the colon. colon.

“I don’t know if humans will be interested in cube-shaped sausages in the future, but this could change the way we shape soft matter, or how we manipulate soft robots in the future.”

Laura Ghandhi, development editor of Soft matter of the Royal Society of Chemistry said: “This is a great example of how cross-disciplinary research and a passion to question everything can produce surprising and useful results. It also shows how creative approaches in science can inspire a passion for research. and stimulate. lasts a lifetime. “

The team of Australian and American scientists received an Ig Nobel Prize in 2019 for “research that makes you laugh and then think”.