Physicists Decode the Science of Poop Coils
AMSTERDAM/PARIS – A team of three physicists from the Netherlands and France has published a study in Nature Communications analyzing the coiling patterns of animal feces, with a specific focus on the castings of the lugworm (Arenicola marina).
The Key Findings
The width of lugworm poop coils remains constant, unlike the tapered shape of the standard poop emoji.
The study reveals that the coiling follows the laws of elastic rope-coiling theory. The distinctive shape results from the upward extrusion of the material against gravity, combined with the specific stiffness of the fecal matter.
This structure is not random. Researchers believe it likely prevents the worm's burrow entrance from clogging or collapsing under tidal forces.
Background and Methodology
Charles Darwin himself studied earthworm castings in his final work, describing the coiled tower-like spirals observed in nature.
To recreate and study these dynamics, the researchers used pea dough, rice noodles, and spaghetti as physical analogues. Interestingly, the study notes that human fecal morphology can exhibit similar coiling patterns when defecated from a height.
Implications and Future Plans
The study provides a physical model for how organisms use mechanics in functional morphology, bridging biology and physics.
The authors plan to propose a second poop emoji to the Unicode Consortium representing upward-extruded feces.