Olivella biplicata, the purple olive, ploughs a crazy quilt of trails on intertidal sands. A good low tide will reveal Olivella’s handiwork on most any exposed Pacific beach between southern Alaska and Baja California.
What motivates the shape of the trails?
Have a look at the purple olive, a little intertidal snail, only an inch long.
Last low tide Olivella left me these and I’m posting them as my response to Numbers.