While we were walking along the beach, we noticed that the surface of the sand was covered in countless tiny holes and little piles of sand around them. Curious about what had been leaving these little remnants, we had to do a quick dig and see what we could find. My best guess is that what we were seeing were holes and castings made by sand worms or lugworms, which are apparently abundant at low tide. Based on the number of castings we saw, it seems that these little creatures have quite a healthy population. I understand that they are also used for bait. Quite an impressive impression they had left on the otherwise flat stretch of sand.