The Lesser of Two Crab Cleats

Fiddler crabs played a big role in our series called the lesser of two crab claws about asymmetry and nature. Here they are once more or at least two species of fiddler crab anyway. In a couple of species, you see male fiddler crabs essentially to some degree building something out of it next to their burrow. This is just like, I mean, picture kind of like a pile of sand.