Gerald Durrell, My family and other animals, Londres, Rupert Hart-Davis, 1956.

There doesn’t seem to be anything else that’s particulary exciting..Ah, yes, I didn’t notice… there is rather a curious caddis larva… there, d’you see it ?…um..it appears to have made its case of the shells of certain molluscs..It’s certainly very pretty.

At the bottom of the little bottle was an elongated case, half an inch long, constructed out of what appeared to be silk, and thick with tiny flat snail-shells like buttons. From one end of this delightful home the owner peered, an unattractive magot-like beast with a head like an ant’s. Slowly it crawled across the glass, dragging its beautiful house with it.
« I tried an interesting experiment once. » Theodore said. » I caught a number of these…er…larvae, and remove their shells. Naturally it doesn’t hurt them. Then I put them in some jars which contained perfectly clear water and nothing in the way of..er.. materials with which to build new cases. Then I gave each est of larvae different-coloured materials to build with : some I gave very tiny blue and green beads, and some I gave chips of brick, white sand, even some…er… fragments of coloured glass. They all built new cases out of these differents things, and I must say the result was very curious and …er… colourful. They are certainly very clever architects. »