The larva (caterpillar) of this moth (order Lepidoptera) decorates (camouflages) its silken cocoon with materials from its environment, including conifer needles, pieces of twigs, leaves, lichens and grains of sand. The unique cases are often characteristic for each species. In fact, this family of moths are often called "case moths." Depending on the species, bagworm cases range in size from less than 1 cm to 15 cm (6 inches). They are usually innocuous to humans, although some cases can be rather unsightly. Caddisfly larvae of the insect order Trichoptera make very similar cocoons decorated with materials from their aquatic environment. The dreaded clothes moth larva also makes a clever little cocoon.

Left: Illustration by Edward Julius Detmold. Plate from Fabre's Book of Insects (1921). Courtesy of Wikimedia Commons.