Caddisfly larvae live in streams and other fresh water sources, housing themselves in tubes they have created from items in their natural environment. Using sand, pieces of shell, etc., the caddisfly, a close relative of the butterfly, uses silk to connect and upholster their protective tubes. A naturalist at heart, Mr. Duprat experimented with the larvae, placing them in a home aqaurium with pieces of gold, gold rods, semi-precious, and precious stones. They immediately went to work, creating this:

Duprat describes himself in the following video as an “architect” laying the plans and watching them take shape. In another article I read, he talked of puncturing the tubes at times, and placing new stones like opal, coral, diamonds, and rubies in the aquarium, so the larvae would “repair” the tube, and thus create something with more varied material.

Video: https://www.youtube.com/watch?v=e78hni1LoSo