Is Every Spider Web Unique? Exploring the Factors That Affect the Structure and Composition of Cobwebs

Spider webs are some of the most beautiful works of natural art. They are made of silk, which exhibits high tensile strength and extensibility. What makes these structures even more fascinating is that spiders are mostly blind creatures, yet they can weave complex webs using various types of silk.

How Do Spiders Make Their Webs?

Spiders possess structures on their abdomen called spinnerets, which serve as their silk-spinning organ. Different species of spiders have different numbers of spinnerets, but most have a cluster.

At the end of each spinneret is a collection of spigots that look like nozzles. A single thread of silk comes out of each. Although this structure seems like an icing nozzle, the silk is pulled by gravity or the spider's hind leg. Inside the spider's body, the silk is actually in liquid form.

In constructing the web, spiders begin by throwing multiple lines of their silk thread into the wind. As the thread becomes longer, the wind carries it to a nearby object. Once the first line is anchored, the spider can build a web frame.

Once the spider has completed the frame, it will add footholds to the structure. Both the frame and the footholds are not made of sticky threads. When the cobweb is almost complete, the spider replaces some foothold threads with sticky ones, leaving enough foothold in the center to wait for prey.

Do Spiders Create Unique Webs?

There are 48,000 known species of spiders worldwide, all with spinnerets. However, not all of these species spin webs. Some spiders hunt for food and use their silk to make tiny "houses" to hide in. Others use silk to build traps and tools such as slingshots, silk pulleys, and oxygen-holding nets for underwater breathing.

The most famous spider web pattern is called orb web, characterized by a wheel-like structure with a spiral and spokes that radiate outward from the center. They are made by less than 10% of known spider species.

Orb webs are ideal for catching flying insects since they are nearly invisible and provide a wide area for capturing prey. A research study published in 2012 reveals that spider webs are characterized by a highly organized pattern that optimizes their function. Although they all may look very similar, no two orb webs are precisely alike. There are also instances when orb webs resemble each other, but with some details that differ between species.

All orb webs follow a similar geometry. The spider lays down a few threads which center on a point, creating a Y shape. Then, it will build a frame around this shape while adding more threads to the middle. Once a general strong shape is established, the spider will move to the middle of the web and start making the auxiliary spiral.

Most spider species do not build webs this way but instead design a chaotic appearance and structure. These webs are even more different from each other than the basic orb web. This makes every orb web unique from each other.