In many rivers they are the most consumed food item during the mid-summer months. Caddis flies are of the insect order Trichoptera , which means hair wing. All caddis have fuzzy wings. Like butter flies and moths, caddis go through a true metamorphosis. They have a larval, pupa and adult stage.
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.