Caddisfly larva cases are a challenge to find in streams. The little larvae build cases out of sticks, stones, leaves, or snail shells depending on the species. This one is made of both stones and sticks. If you find one of these cases, pick it up and see if it is empty or if it is occupied; the larva will sometimes poke its head out. Just be sure and put it back in the water so it doesn't die! Some people put the larvae in water with semi-precious gemstones to let the larvae make bejewled cases which are used to make earrings and necklaces!