Caddis are small insects that belong to the order Trichoptera. They are known for their aquatic larvae, which build protective cases using silk and various materials found in their environment. These larvae are important food sources for many fish species, making caddisflies a crucial part of freshwater ecosystems. Adult caddisflies have long antennae and wings that are held roof-like over their bodies when at rest. They are often mistaken for moths due to their similar appearance. Caddisflies are commonly found near streams, rivers, and lakes, where they play a vital role in the food chain.