Spider Silk Facts & Information

Some spiders use their silk for mobility by making sail-like silk structures that enables them to travel distances by riding wind currents - a procedure known as ballooning. Some orb weaver spiders employ their silk to act as a slingshot that flings them at their prey.

While some species of spiders that are highly venomous to humans and animals, most are beneficial since they prey on insects that are known pests and disease spreading critters. Spider silk is stronger than most man-made or natural fibers on Earth.

For example, spider silk is stronger by weight than steel. Spider silk is thinner than human hair. Organs on the spiders' legs enable them to detect vibrations in the web’s silk that may alert the spider to determine when prey is tangled up in the web.

Types of Spider Silk

There are several types of spider silk and each one has a unique aspect in spider life. Spiders are able to produce up to seven types of silk, each type produced by one of its seven silk glands. Individual spiders do not possess all seven glands but has at least three if it is male (dragline, attachment and swathing silk) or four if it is female since females produce one additional kind of silk that is used for her egg sac.

The seven types of silk and the uses are:

• Cylindriform gland for producing egg sac silk

• Achniform gland for producing silk that binds up and envelops prey

• Ampullate gland (major and minor) for producing the non-sticky dragline silk used to connect the spider to the web and function as a safety lines in case a spider should fall or move outside of the web. Dragline silk is the strongest kind of silk because it must support the weight of the spider.

• Pyriform gland for producing attaching threads and attachment discs that anchor a silk thread to a surface or to another thread.

• Flagelliform gland for producing the web material that makes up the core fibers of sticky silk that helps prevents prey from getting out of a web

• Aggregate gland for producing droplets that produce the surface part of sticky silk and create the adhesives that are deposited along the threads.

Mating glands for producing sperm webs on which males deposit sperm and subsequently transfer it to their front palps awaiting placement on a female’s genital organs.

What is Spider Silk Made From?

Spider silk is made of connected and unconnected chains of liquid proteins whose chemical composition varies with the type of function the spider’s silk performs. Ever wonder why a spider’s old, unused web hangs around long after the spider has moved on? Silk is very acidic which is one of the reasons that spider silk in not attacked by bacteria or fungi and thus remains in the environment a long time.

How Do Spiders Produce Silk?

Spiders use their silk glands to produce silk solutions which enter into the spinning tubes or the spider’s spinnerets. Spinnerets have spigots (“faucets”) that connect to the silk glands. Silk starts as a liquid protein stored in the spider’s internal silk glands before hardening into a solid form. Once the silk is solid, spiders use their spinnerets, which are located on the outside of their abdomen, to produce the silky fibers for webs. Silk is hardened by the spider acidifying the silk, a process similar to that used in the commercial manufacturing process of making industrial fibers such as nylon. Spiders may sometimes eat their silken webs and use it to make new silk

Spider Silk Uses by People

• Spider silk has amazing strength and rivals many man-made materials, including nylon, Kevlar®, and high-tensile steel and involves the potential use of spider silk as an incredibly strong and versatile material.

• Silk was used as the crosshairs in optical targeting devices such as guns and telescopes until World War II and people in some societies still use spider silk in making fish nets.

• A few people in Madagascar and other locations around the world still use spider silk when making clothes.

Spider Control

Spider control for different homes and areas often requires an integrated pest management program that is tailored to your situation. Keeping spiders and pests out of your home is an ongoing process and not a one-time treatment.