Protective Cases of Caddisfly Larvae

Caddisflies are an order (Trichoptera) of insects with approximately 12,000 described species. They can be described as small moth-like insects with two pairs of hairs membranous wings. One of the most interesting characteristics of the caddisfly is the ornate and highly intricate protective cases they build as larvae.
The caddisfly larvae is aquatic and can be found in a variety of habitats such as streams, rivers, lakes, ponds, springs and even temporary waters. The larvae collects whatever material it can to form its protective case, bonding the various materials together with silk that it excretes from its salivary glands near its mouth. [Source]
Different species of caddisfly tend to use different materials for their protective cases making for a diverse array of cases. Artists have even taken it a step further, cultivating their own cadisfly and providing them with unique building materials like gold and pearls to create ornate protective cases that are preserved for their artistic merit after the cadisfly has undergone metamorphosis.