Sand Piranhas aka Sand Fleas are small crustaceans (Excirolana Chiltoni) that enjoy eating human flesh. Although these little creatures only take miniscule bites of flesh at a time, it can feel painful like a razor blade when they bite your feet. I've seen these little guys plenty of times, and never knew what they were, or that they could bite.
These feisty crustaceans are related to Roly Polys, and burrow in the sand to hide from predators. They're translucent, tiny, and very resilient. They even help clean up animal carcasas on the beach, keeping beaches smelling nice and looking pleasant.
To spot a group of them from afar, simply keep an eye out for little squiggles in the sand. If you get bit by one it's not the end of the world, but you definitely wouldn't want to hang out in a bathtub full of them. After watching this video, I might have to invest in some water shoes.
See also: Beach bully cited by California Coastal Commission
