How Do Spiders Make Silk?

Spider silk is a fibrous protein material produced by spiders. It is stronger than steel and is extremely stretchy. Some spiders use it to make webs or wrap their prey.

A spider can produce silk using a variety of glands. Most spiders have four to six silk glands. These glands can store spidroins, which convert into solid fibres.

There are several different types of silk, including dragline silk, egg cocoon silk and capture-spiral silk. Each of these uses has its own unique properties. Some are extremely ductile and extendable, while others are rigid and brittle.

Some types of spider silk can absorb energy effectively. These can also be used for transportation. Other silks are used for protective structures. Some are translucent, while others reflect ultraviolet light.

Spider silk is produced by spinnerets, special organs that connect to the silk glands. They have spigots that help to collect and spin the silk. The number of spinnerets varies according to species.

In order to spin the silk, a spider needs a complex duct system. The structure of the duct makes it difficult to copy. Some species may even have a specialized valve. The valve helps to regulate the thickness of the silk fiber.

Some species leave a trail of silk when venturing from their shelter. Some spiders hang from a drop line, which can act as an emergency line.

Some species build webs and then eat their own unused silk. These include the European garden spider Araneus diadematus.