We know why spiders make webs—to catch their dinner. But howspiders make webs is complicated. There are lots of different kinds of spider webs.
Sheet weavers make webs that look like a flat net. Tangle-web makers, like the black widow, create messy, disorganized cobwebs. Funnel-web spiders wait at the narrow end of their shaped web, ready to pounce on bugs that get their feet tangled. Triangle weavers stretch their webs taut, like a bowstring. When prey lands on the web, the spider lets go. The web flings the spider at its victim. And then there are spiders that spin a small patch of web and use it as a net. They hang and wait for a little bug to walk below them. Then they drop the net onto their prey.
If we asked you to draw a spider web, you would probably draw one like the orb weaver spins. Your first line might be at the top. The spider also starts there. It lets breeze carry a loose thread of silk until it catches on another twig. Then the spider creates another loose bridge thread and uses its own weight to drop and extend the thread into a Y shape. Outside anchor lines are stretched next, followed by corner reinforcing lines. So far, none of the threads are sticky. When the outer framework is complete, the orb weaver makes lines to the center of the web—still not sticky. Next, the spider goes round and round connecting each radial thread. Sticky? Nope. Working from the outside, it makes a spiral toward the web’s center. Finally, it is time for sticky work. It is time to spin the most important part of the web, the capture spiral. That spiral also works from outside in, but along the way, the spider releases fluid from one of its silk glands. Tiny beads of adhesivecoat the capture spiral. Finally, the spider can wait for dinner to arrive.
But you are waiting, too. You are waiting to hear how a spider keeps from getting stuck in its own web. Long ago, people used to think the spider just avoided walking on the sticky threads. Perhaps spiders do have ways of moving that keep them from getting stuck. But in recent years, scientists have suggested that spiders might also coat themselves in a sort of lubricant . . . but they’re not sure. So it looks like we’ll all have to wait to learn more. Or maybe you will become anarachnologistand help discover the secrets of spiders.
