Silk moths at a reed basket

After nearly 5,000 years of selective breeding, silk moths have lost the ability to fly and cannot survive without humans.
Silk is a by-product of silkworms gorging on the leaves of mulberry trees. They spin cocoons which are then harvested and boiled. The threads for weaving are drawn from the resulting floss. But while sericulture is similar world-wide, there are major regional differences. In Cambodia, "yellow" silkworms evolved to match the tropical climate, while in the more temperate regions of China and Japan, higher-producing "white" silkworms are the insects of choice.