Caddisflies that are in the larval stage eat decaying materials, such as plants and algae. Caddisflies are mostly herbivores and scrape decaying materials off of rock, but some do eat small animals.
Once fully grown, caddisflies do not eat. Because these invertebrates only live for around a month after becoming an adult, they require very little food and only feed on liquids. Caddisflies live in bodies of freshwater, including lakes, swamps and rivers.
There are over 1,300 different species of caddisflies in the United States and over 12,000 in the world. Each type of species is able to adapt to different environments. The aquatic insects build houses spun out of silk, and some also use leaves and twigs to construct their cases, which are also known as houses. The caddisflies begin building as soon as they hatch, and they use a sticky substance that comes from their mouth during the building process. The houses serve as protection from predators and the larvae stay in the casing until they become fully grown. It can take up to 2 years for larvae to become fully grown.
Caddisflies are a member of the moth family, and they have many predators. For this reason, many serious fishermen use artificial flies to attract fish. Caddisflies are also known as sedge-flies or rail-flies. Fossils of caddisflies date back to the Triassic age.