Spider webs are fascinating because they are beautiful and serve many purposes. Not all webs are used to catch prey and some spiders do not build webs at all. We usually use the word spider-web to refer to fresh webs that are still being used by a spider and the word cobweb to refer to old and dusty webs that do not actually have a spider still living in it.
Why do Spiders Spin Webs?
Spiders begin a web by throwing multiple lines of their silk thread into the wind. As this thread becomes longer, the wind carries it to a nearby object. Once the first line is anchored, the spider can now go about building the frame of the web. Once it has completed the frame it begins to add footholds. The frame and footholds are not made of sticky threads. Once the cobweb is almost complete, it goes back and replaces some of the foothold threads with sticky ones, leaving enough of a foothold in the center to wait for its prey.
Not all webs are used to actually catch prey. Some spiders will spin very simple webs and wait there to jump onto their victims. While some will build nets and suspend them underneath their bodies. When they see their prey, they cast these nets over them. Others use it as an alarm system to warn them of predators. Some really clever ones will use a maze of webs to stun their prey, only for them to fall into another web where they get tangled and served for dinner.
See if you can get hold of a digital camera. Go web hunting and take pictures of the different webs you can find. Spiders tend to build their webs between trees, or in corners of dark and damp parts of the house.
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