Depends on what you're looking for. Either you gotta look in the water and see what's crawling around or you gotta poke through the sand.

[He pushes one hand into the sand and feels around until he hits something with a smooth back and way too many scrabbly little legs.]

Gotcha! See?

[He holds up the sand flea for Roxas to see. It's a big one, so he's rather pleased with himself over it.]