Silk
Silk moths lay eggs on specially prepared paper. The eggs hatch and the caterpillars (silkworms) are fed fresh mulberry leaves. After about 35 days and 4 moltings, the caterpillars are 10,000 times heavier than when hatched and are ready to begin spinning a cocoon. A straw frame is placed over the tray of caterpillars, and each caterpillar begins spinning a cocoon by moving its head in a pattern. Two glands produce liquid silk and force it through openings in the head called spinnerets. Liquid silk is coated in sericin, a water-soluble protective gum, and solidifies on contact with the air. Within 2–3 days, the caterpillar spins about 1 mile of filament and is completely encased in a cocoon. The silk farmers then heat the cocoons to kill them, leaving some to metamorphose into moths to breed the next generation of caterpillars. Harvested cocoons are then soaked in boiling water to soften the sericin holding the silk fibers together in a cocoon shape. The fibers are then unwound to produce a continuous thread. Since a single thread is too fine and fragile for commercial use, anywhere from three to ten strands are spun together to form a single thread of silk.
Oligotoma nigra
The entire life cycle of the black webspinner is typically completed within a year. They are a hemimetabolous insect species, meaning that they have incomplete metamorphosis. During developmental stages the nymphs produce silk from silk glands. The glands are located on the basal segment of the foretarsus. they use this ability to create silk tunnels for protection from predators and to store food. Eggs are laid within the silk tunnels. When the nymphs hatch they expand the network of tunnels. This network continues to expand as the insect matures. The vast majority of their life is spent within the silk tunnel.