Caddisflies are popular on the fly-fishing scene, where anglers do their best to emulate the stream-scavenging creatures in their mature form. But like most aquatic insects, caddisflies actually spend the vast majority of their lives underwater in their larval stage, where they cling on for dear life against ceaseless stream currents. Mercifully for these minuscule creatures, they’re hatched into the world with something of a superpower for surviving the tough terrain: a versatile silk, dispensed from glands under their chin. Natural-born builders, the larvae deploy the sticky substance to fashion cases for themselves out of small pebbles that guard them against careening objects, and provide camouflage and protection against predators. This entry in the science-documentary series Deep Look takes a quick dive into the lives of these impressive improvisational engineers, including how their waterproof adhesive has inspired bioengineers hoping to create less-intrusive internal stitches for the human body. Read more about the video at KQED Science.