fiddler crabs at work

all along the edge of the water at wellfleet, there are these piles of little balls of sand. i was told that these were made by fiddler crabs, but no one could tell me why they did this. after a brief internet search, i learned that they make balls of sand to plug the entrance hole into their burrows during high tides. when water covers their homes, a tiny pocket of air is trapped inside for them to breath. ingenius. and bloggable.