We’ve all seen a spider web, and we all know that spider silk is incredibly strong. But is there more to spider webs than that? As it turns out, spider webs are designed to store mechanical energy, just like springs.
When you apply force to a spring it will be either in a state of compression or tension, thus storing energy. If you remove the force, the stored energy is transformed into kinetic energy, with the spring returning to its original position in accordance with a physical principle known as Hooke’s Law. According to Hooke’s Law, the spring’s displacement is equal to the amount of force applied. So how does this relate to a spider’s web?
Some spiders are experts at implementing this law into their structures, and they are called Triangle Weavers. Their webs are similar to slingshots – when the Triangle Weaver lays down its web, it will pull on one of the three corners to create tension. Then, when the prey is near the web, the spider will release its corner, converting the stored energy in the web into kinetic energy. This propels the web and captures the insect.
Black widows on the other hand will build cobwebs, which have a scaffold structure. This spider uses Hooke’s Law differently. It will attach strands of silk to the floor under tension, and when an insect passes through these strands and breaks them, the kinetic energy within them is released pulling the insect up into the cobweb and trapping it inside.
So what we see here is that spiders rely on more than just the stickiness of the silk in order to trap their prey. When kinetic energy is added into the mix, the number and types of insects that can be trapped grows, and this allows the spider to be a much more effective predator. Now when you see a cobweb inside the home, you can tell how exactly the spider will use it to catch its prey. It is very interesting that spiders have evolved the ability to use kinetic energy when building their webs, as if these structures weren’t amazing enough already.
However, seeing cobwebs all over your home or yard is never pleasant, so we will often try to get rid of them and the spiders that build them. If you have a large spider infestation in your home, contact us today and we can set up an appointment to remove it.