Millicent E. Selsam, Underwater Zoos, New York, William Morrow & Company, 1961.

It drags around a case, or tube, that may be made of sticks and stones, or of leaves, sand, pebbles, and shells, all held together with a sticky saliva. You can make the caddis worm form a new tube out of materials you give it. Put it in a jar with water about an inch deep, and provide it with thin strips of paper, small glass beads, sequins, or any other material you have. You can prod the worm out of its case by gently poking its rear end with a stick. Remove the old case. The worm will soon start to build a new home. This time it will be a currious collection of beads, paper, sequins, and whatever else youp ut into the jar.