James A. Bateman, Animals Traps &Trapping, Londres, Coch-y-Bonddu, 2003.

The larvae of caddis flies live in freshwater and most of them construct tubes to protect the unarmed part of their bodies and either wait within for food material to come drifting through the water, or else move over plants upon which they also feed. In these tube-builders, a basic tube of silk is produced and on to this are sealed pieces of all kinds of matter imaginable, such as sand granules, leaves, leaf fragments, stalks, pieces of stick and even shells of small snails.