Aquatic insects are incredibly fascinating little creatures that spend at least a part of their life cycle in streams and then sometimes move onto land or take to the air as adults. They include bugs that you may be familiar with such as stoneflies, mayflies, dragonflies, and caddisflies. We provide here several illustrative photographs of the larval stages of insects commonly found in freshwater habitats to kick start your imagination. Please roll over each of the pictures to see what the adult stage looks like. In addition to being downright amazing, aquatic insects are also widely used as indicators of water quality!