How Does a Spider Spin Its Web?
A spider spins a web out of silk that it makes inside its body. The silk comes out in thin liquid threads that harden when exposed to the air. The spider attaches the silk threads to a branch or fence in a special pattern. Some spiders spin complicated wheel-like webs. Others spin simple sheet webs.
Some of the spider’s silken threads are sticky. Flies and other insects that the spider eats get caught in the sticky threads. The spider, however, is protected by an oily covering on its body. This allows it to walk right across those sticky strands of web.
Making webs is instinctive for spiders, which means nobody has to teach them how to do it. They are born knowing how.
When a spider begins a web, it releases a silk thread. It anchors the thread to some object — a branch, a corner of a room, a doorframe — wherever it builds its web.
As the spider moves back and forth, it adds more threads, strengthening the web and creating a pattern. Lines that go from the center of the web outward are called “radial lines.” They support the web. Threads that go around and around the web are called “orb lines.”
When a spider catches prey in the sticky strands of its web, it approaches the trapped insect and uses its fangs to inject venom. The venom either kills or paralyzes the prey, allowing the spider to enjoy its dinner in peace.
Not all spiders use webs for food, however. Some don’t build webs at all. Other spiders chase their prey. Some even make sticky nets, which they throw over their prey when it gets close enough.