Scientists have explained why the feces coming out of the intestines of wombats have a shape close to a cubic one. It is reported by the ABC TV channel.
Scott Carver and his colleagues have been studying wombat feces for years. The first known work was published by them in 2018, for which scientists were awarded the Ig Nobel Prize – an ironic award for funny and not very (at first glance) important discoveries. In 2021, the research team expanded on the topic and found that wombat feces owe their unusual shape to the uneven distribution of intestinal tissue thickness. In recent work, biologists have determined why excrement is so uniform.
“[In previous work] we found out how the corners are formed that give the feces the shape of a square in section. But we have not established why they break into fragments at such regular intervals and turn out to be consistently small and approximately equal in length, ”the scientists say.
To clarify this issue, the authors turned to the knowledge gained during the study of lava solidification by volcanologists. When the lava solidifies unevenly, periodic structures can appear, like the Irish “Road of the Giants”, consisting of rows of hexagons. Presumably, the analogue of the solidification of lava is the drying of excrement.
The authors tested their hypothesis on the model of a drying paste. To do this, they used cornstarch, a plastic model of the intestinal tract of wombats and infrared lamps. The latter dried the starch slurry placed in a plastic tract at various capacities. As a result, scientists found that the more intense the drying process, the smaller and harder pieces the hardened slurry was broken into.
To confirm their hypothesis, the authors turned to the reference literature. They found that when the water content of the feces falls below 70 percent, cracks form and the animals excrete the feces in balls. Spilled cowpats form at around 85–90% moisture content, while wombat feces are very dry and contain 65% water.