It’s always fun to flip over rocks to see what’s hiding out. At first glance, one might think this is just a small piece of wood on a rock. This is actually a case-building caddisfly. The materials a caddisfly uses to build its case can help identify the type of caddisfly. This one primarily used bits of wood to create its casing. If you want to learn more about this fascinating macroinvertebrate, check out this video from KQED’s Deep Look.