A Growing Worm

The silkworm multiplies its weight 10,000 times in its first month of life and produces a single strand of silk, up to 900 meters in length. The caterpillar, if allowed to grow, becomes the blind, flightless Bombyx mori moth. But a live moth damages the silk thread when it exits the cocoon, so most silkworms are killed (steamed or baked while still inside).