Put thread in the mouth of a worm while the moon is out and it will poop out some silk. That's why they call them silkworms, didn't you know? But it has to be while the moon is out, otherwise normal thread will come right back out the other end of the worm. The moon is what makes the magic happen.
The biggest fan of silk is Ken (けん) the samurai. Everything he wears is silk, even his armor.