Spiders are one of nature’s most magnificent engineers! Watch to find out why and learn more about how spiders make their web and the different types of webs they make! #STEMvee
[Video Description: Barbara, a white woman with curly red hair, is sitting on a tan chair and wearing a dark purple long sleeve sweater in front of a gray background.]
Transcript: If you’ve ever seen a new home being built, you know that the workers use wooden boards to frame the house. Instead of the boards, spiders produce silk threads to build their web homes. They are probably one of nature’s most magnificent engineers. How do spiders produce silk? Spiders have an organ on its abdomen called a spinneret. A spinneret has silk glands that will produce different types of silk.The silk threads can be tthin or thick, sticky or dry, beaded or smooth. Any individual spider can make up to seven different types of silk, but most generally make four to five kinds. The threads a spider uses to construct its web begin as liquid, but they dry quickly in the air. Spider’s silk is flexible, tensile, and strong. This amazing material is about twice as strong as steel. How does a spider build a web? I will focus on one group of spiders as an example of how they build a web. The spider starts building their web by creating a length of sticky silk which it dangles from a point. It is so light it gets caught by the breeze and sticks to a second point on surrounding vegetation or solid structures. When it sticks to the second point, the spider feels the change in the vibration. The spider reels in and tightens the first strand, then carefully walks along it and strengthens it with a second thread. This process is repeated until the thread is strong enough to support the rest of the web. This first strand of silk is called the bridge thread. Once the bridge thread is firmly anchored in place, the spider crosses this thread, creating a second thread. Eventually the weight of the spider pulls it down, pulling this second thread with it. And, the spider anchors it to surrounding vegetation or solid structures. Then, the spider creates non-sticky silk threads. From there, the spider creates radial spokes, radiating from the center. Then, the spider makes an auxiliary spiral to bind all the radial spokes together. Then, the spider switches to sticky silk threads. From this, the spider spins a final spiral web, called the capture web, building this one from the outside in. Why do spiders build webs? Webs serve as pretty much defense and offense. Vibrations in the web strands can alert the spiders to predators. Webs are also used to catch prey. Sometimes spiders eat their own webs when they are done with them, as a way to replenish the silk supply for future webs. Do you know that there are different groups of spiders that produce different types of webs?! I will name four common types of spider webs. Orb webs – are the classic, wheel-shaped webs. They allow spiders to fully enter vertical space and occupy a new niche. Tangled webs – are also known as cobwebs as they appear messy and shapeless. They are intentionally designed to be a jumble of threads to entangle an unsuspecting insect. Sheet webs – are slightly concave webs strung across plants. They act like a deadly hammock to knock an insect off its flight course. Funnel webs – are the sheets that span the exterior of the funnel. They are used for many purposes: a hideaway from predators, to store eggs, and as a surprise maneuver to capture prey. Now, you know different types of webs — let’s go out and have an adventure in spidering!
