Why is a Spider’s Web So Complex?
WouterA spider web is a complex structure made of sticky silk. It allows spiders to trap and catch prey. They also rely on the web’s vibrations to alert them to the presence of predators. Despite its complexity, the design and function of a spider’s web are impressive.
One of the biggest questions scientists have about spiders is how they construct their webs. Several families of spiders are known to weave sticky webs. However, these groups have different designs. In some cases, the web is constructed from sticky material, while in others, it is simply made of dry silk.
For example, the Scoloderus spider uses a ladder-like structure to capture a moth. When the moth’s scales flake off, the ladder portion of the web traps it. The ensnaring threads create a dense spiral.
Other types of spiders, such as the orb-weaver, lay down a temporary spiral. The spider rolls the spiral out from the centre, and then replaces it with an adhesive thread.
Another type of spider, the bolas spider, makes a unique web. Instead of using venom, the bolas lays down a single thread with a sticky droplet at the end. They use this technique to attract male moths. They attach this thread to their perch. The odour of the bolas spider mimics that of female moths. This attracts the male to the female. The bolas spider then holds on with its one leg.
While many species of spiders construct sticky webs, not all of them are active hunters. In fact, some spiders build their webs solely for decorative purposes.
