All stages are vulnerable and are eaten by trout. Essentially caddis larva fills the role of the caterpillar. It is the juvenile stage which does the feeding and growing. In many ways resemble caterpillars. They have large heads with well developed mandibles, cylindrical bodies and short powerful legs.
Many species build houses from gravel or vegetable matter.
Some of these houses are stationary, many are mobile. Other species roam unencumbered in the substrate. Still others build and trap food with spider type webs. Some species are herbivorous others are predacious. Caddis larva come in a wide range of sizes and colors.