Leonard Moore, Pond Life, Hamlyn Junior Nature Guides, Londres, Hamlyn, 1975, p. 39.

The larvae of caddis-flies are some of the most interesting of pond animals. Many years ago, there were men who would walk from village to village with things to sell. Often they would sew their goods to the outside of their coats so that people could see what they had to offer. These men were sometimes know as caddis men and this is how the caddis-flies got their name. A caddis-fly larva is a little like a caterpillar, but the front part of its body has a tough skin. The back part is soft so the larva makes a silk tube around it and sticks grains of sand, or tiny shells, or pieces of twig or leaves onto it rather as the caddis men put things on their coats. There are many different kinds of caddis-flies and the larvae of each kind use the same materials for their tubes. As they grow, they add on pieces to the front end of their case to make them larger. A larva can walk about in the pond, looking for pieces of plant on which to feed, but if there is danger about, it can pull the front part of its body back into the tube and this will help to protect it. Sometimes, though, a fish may eat the larva, case and all !