Spiders are remarkably strong for their size. On average, spiders can lift about eight to ten times their body weight, and some species can lift or carry up to 170 to 200 times their body weight. This strength far exceeds what humans can do relative to our weight; the strongest humans can lift nearly three times their body weight. This extraordinary proportionate strength is partly due to their small size and the properties of their muscles and exoskeletons. In addition to their physical strength, spiders produce silk that has incredible tensile strength—stronger than steel by weight—which helps them build resilient webs to trap prey. The strength of spider silk is enhanced during its creation by the spider stretching the silk fibers, aligning protein chains to increase durability. Overall, spiders' strength is impressive both in lifting capacity relative to their size and in the strength of the silk they produce for their webs.