How Can Spiders Use Silk?

Spiders use silk to build webs and nests, and to create cocoons. Silk can also be used by spiders as fishing lines. In fact, some species leave a trail of silk when they travel from their home to a new habitat.

Spiders produce several different types of silk. Each type serves a particular function.

For example, dragline silk is used as a lifeline and is very strong and elastic. Male spiders deposit sperm on sperm webs. Similarly, female spiders spin protective cocoons for their young.

Silk is also used for structural support and to transmit vibration efficiently. Scientists have used silk to make medical bandages and optical fiber cables. There are even some silk-based bulletproof armors. Various types of silk have been found to absorb energy effectively.

Silk is composed of a mixture of proteins. These protein chains form the inner and outer sheathing layers of the silk. They get their stiffness from highly ordered alanine peptide crystals. The threads are anchored with attachment discs.

Some of the silk used by spiders is very sticky. The sticky strands adhere to aerial prey. Several types of silk are used for trapping, catching, and wrapping. Among them are aciniform, ampullate, flagelliform, cribellate, and dragline silk.

Spiders use silk to construct complex webs, and sometimes for capturing and ensnaring their prey. Depending on the species, their webs vary in size and structure. While some are incredibly large, others are tiny and delicate. And some can travel long distances in the wind.