As anyone who has ever unwound a string of holiday lights or detangled a lock of snarled hair knows, undoing a knot of fibers takes a lot longer than tangling it up in the first place. This is not so for a wily species of West Coast worm. Found in marshes, ponds, and other shallow waters, California blackworms (Lumbriculus variegatus) twist and curl around each other by the thousands, forming tightly wound balls over several minutes. In the face of a predator or other perceived threat, the worms can instantly…
