Have you ever considered where all those curly-wurly squiggly designs come from on a beach. I had presumed it was some sort of sand and sea related physical process – belonging to the realms of physics or chemistry. But I was wrong. Quite wrong!
Lugworms are found in sandy marine mud all over the world. They ingest the sandy mud at one end, and excrete digested sand at the other. They can process a cubic centimeter or more of sand every hour. The worms digest the bacteria and other microorganism in the sand, in much the same way that earthworms process soil.
What made these swirls in the sand? – https://askanaturalist.com/what-made-these-swirls-in-the-sand/