How Do Spiders Make Cocoons?

Spiders are arachnids that produce silk, a natural fibre made from protein molecules. They use silk to build nests, wrap their prey, and make intricate webs.

There are many species of spiders, with some species producing more than one cocoon per year. Some are called “dormant” and remain dormant until spring. Others have an active cocoon-making cycle that lasts a couple of years.

Silk is produced inside spiders, from special glands in their abdomen. When spun, the silk is highly extensible and has exceptional tensile strength. These threads are used to wrap prey, as drop lines, and as anchor lines. Depending on the species, different kinds of silk are excreted.

Cocoon-containing webs are more resistant to damage by flying insects and are three to 40 times stronger than their non-cocooning counterparts. This helps protect the developing larva from predators.

Scientists have long tried to understand how spiders produce silk. Despite these attempts, scientists have not been able to reproduce silk in the laboratory.

Several types of spiders produce webs, including orb, platform, and filmy dome spiders. Orb spiders spin large, round-shaped webs. They need to keep their webs repaired and reconstructed regularly.

Other species produce triangular, dome-shaped sheets of silk. Usually, they secure these sheets with silk strings.

The most common cocoon builders are butterflies and moths. But there are other arachnids that can produce cocoons, such as caddisflies, scorpions, and mites. Those arachnids can also build other structures.

Female spiders produce a protective cocoon to shield their eggs from predators. They build cocoons for several egg sacs in their lifetime.