Using webs Spiders use their silk in a variety of ways. Webs entice prey, silken nests enshroud eggs, and offspring tentatively venture from their webs, exploring beyond the nest yet still tethered to it by a lifeline. Reproduction requires silk too. A male weaves a small sperm web and deposits sperm onto it. He then transfers the web to his palps, which he uses to place the sperm web in a female's genital opening.
Some species use silk in even more specialized ways.
A species that lives in freshwater ponds throughout Europe weaves a diving bell of sorts. The animal anchors the balloonlike structure it creates to an aquatic plant and then submerges, ferrying air bubbles in the bell. A type of sea spider builds a silken hideaway at the intertidal zone, retreating to the protected shell when the tide comes in. Humans have in mind different uses for spider silk. They envision medical products such as surgical thread and replacement ligaments, and military applications including flak jackets, parachute cords, and tethers for planes on aircraft carriers.