The cobwebs are strong, resistant, and can have beautiful drawings, but their main purpose is to catch the prey, as the spiders feel the vibration of the net when an insect falls on it, and attack quickly.
The silk of the cobweb
The webs are constructed with a liquid silk -product protein- synthesis found in the glands spinning (also called spinnerets) that are located in the back of the abdomen.
This silk becomes solid when it comes in contact with the air. Although this immediate change from liquid to solid is one of the most amazing facts of nature, it does not have to do with the contact with the air, but when casting it, the molecules are realigned solidly.
In addition, the spiders are able to choose different thicknesses and types of silk according to the conditions where they will make the fabric. The silk can be very fine and light, although with it thick threads become very resistant.
While some species have sticky silks, others do not have to be silks; as well as there are varieties in the texture of the silk: some can be easily adhered to multiple surfaces by their own protuberances, while others are completely smooth. In that case, they adhere to electrostatic forces.
The old cobwebs and failed attempts are eaten by the spiders, digested and processed to generate new silk. In order not to get entangled in their own cobwebs, it is believed that spiders cover their legs with an oily substance that they secrete from their mouths, although this is not firmly demonstrated.
How Do They Build The Fabric?
The key to forming spider webs is in the wind, especially if they are woven between two trees. Once the silk thread begins to leave the spider, it moves according to the wind and takes advantage of it to give it direction. In general, the spiders draw a first bridge that serves as a point of reference and as a way to mark the territory.
To that initial point they are adding more and more threads, which make the network become stronger and more resistant, and finally, a pattern is created. The lines that go from the center to the outside are called radial and their function is to make the point of support of the network; while the orb lines are the ones that go around.
The funny thing is that many spiders have vision problems, and build these works of silk art solely through the sense of touch.
In general, the same spiders use their fabric as “loose rope”, since they hang upside down from it to be transported from one place to another while they are building the network.
Spiders often build networks at the moment they are not hunting, and as there is a wide variety of arachnids, this can be both at night and during the day.
Did you know how to spiders make their web? Do you like spiders? What would other curiosities about animals you like to know?