"Spider silk is one of nature’s toughest substances, similar in strength to the Kevlar plastic found in bulletproof vests but much more flexible. Kraig Biocraft, a company out of Ann Arbor, Michigan, genetically altered silkworms to produce a fiber that’s similar to pure spider silk. Today, they announced an Army contract to test this so-called Dragon Silk for possible use in body armor.
There’s a reason that silk from worms is cheap but you can’t buy pajamas made from spider fabric: spiders are territorial and cannibalistic, which makes farming them for fabric production almost exorbitant."