Rope made from cobwebs. What is the significance of webs in the life of spiders? Composition of a spider's web

Practical benefits of the web.

Every Most of us are well aware of the web: we have repeatedly encountered cobwebs in the forest, and even in our own home. They brush cobwebs out of the corners with a broom, and in the forest, when they accidentally land their face in them, they shake them off with displeasure.

Meanwhile, spider web is a very interesting and useful natural material in practical applications, the enormous importance of which has today been undeservedly overshadowed by numerous synthetic polymers.

The finest threads of the oldest web were discovered in a piece of amber by workers at the University of Oxford in East Sussex. The age of the unique find is estimated at approximately 140 million years. Until this point, the oldest was considered to be a web in a piece of amber found in Lebanon, dated 130 million years ago, and the oldest spider was found in amber about 120 million years old. Amber, formed more than 100 million years ago, is extremely rare.

Using the most modern ultramicroscopy technologies, scientists were able to identify the oldest spider web, the length of the threads of which was slightly more than a millimeter. Interestingly, the web is similar to the one weaved by modern spiders. The location of the discovered threads made it possible to establish that they were supports for the orb web. The same piece of amber preserved two skeins of ancient cobwebs.

Thanks to this discovery, the paleobiologists who studied it suggested that arachnids are actually much more ancient creatures than previously thought. Previously, it was believed that the wide distribution of flying insects, which served as prey for arachnids, was caused by the appearance of flowering plants on our planet. After studying the discovery of Oxford scientists, it was suggested that the oldest arachnids hunted crawling and jumping insects by weaving webs on the soil surface.

In addition to the cobwebs, the same piece of amber preserved charred particles of burnt bark and sap of a coniferous tree. Presumably, the tree released resin that absorbed the cobwebs and subsequently turned into amber during a forest fire.

Spiders themselves use webs to build shelters, lining burrows, trapping nets and egg cocoons; males make a sperm net out of it for the purpose of reproduction. In the juveniles of some spiders, long threads of web serve as parachutes when dispersing by wind. When making a catch net, the spider first tensions the frame and radial threads, then lays a temporary support spiral thread, and only after that weaves an adhesive spiral catch net, after which the cut bites off the support thread.

Spider web is a protein enriched in glycine, alanine and serine. Inside the arachnoid gland it exists in liquid form. When secreted through numerous spinning tubes that open on the surface of the arachnoid warts, the structure of the protein changes, as a result of which it hardens in the form of a thin thread. Subsequently, the spider weaves these primary threads into a thicker web fiber.

The backbone of the web consists of two proteins: the stronger spidroin-1 and the more elastic spidroin-2. It is the combination of their properties that determines the unique properties of the web.

The web can have a diameter of up to several millimeters and consists of very thin threads. The web is extremely thin and light. To encircle the equator of our planet, it would take only 340 g!

Scientists are most interested in the frame thread of the web, which is unusually strong and elastic. Few people know that spider thread is close to nylon in strength - its tensile strength ranges from 40 to 260 kg/mm2, which is several times stronger than steel. If the web had a diameter of 1 mm, it could support a load weighing approximately 200 kg. Steel wire of the same diameter can withstand significantly less: 30-100 kg, depending on the type of steel. In addition, it is unusually elastic.

Interestingly, when the web gets wet, it contracts greatly (this phenomenon is called supercontraction). This occurs because water molecules penetrate the fiber and make the disordered hydrophilic regions more mobile. If the web has stretched and sagged due to insects, then on a humid or rainy day it contracts and at the same time restores its shape.

Another unusual property of a spider's web is its internal articulation: an object suspended on a spider's web fiber can be rotated indefinitely in the same direction, and at the same time it will not only not twist, but will not create a noticeable counterforce at all.

As you know, people extracted natural threads from natural materials with quite a lot of ingenuity. Subsequently, fabrics appeared from such threads - from wool, cotton, flax, nettle, and even from the finest threads of silkworm cocoons. However, the use of the web opens up new prospects in this direction, because is an excellent material for making durable and lightweight fabrics.

The first attempt to make such fabric was made three centuries ago by the French entomologist Bon, who presented his proposals to replace imported silk with spider silk to the Royal Scientific Society. As a sample, stockings and gloves made from spider silk were included. The scientist’s idea did not find support due to the difficulty of mass breeding of spiders. Nowadays there is a solution to this problem, but the emergence of a large number of synthetic threads has sharply reduced the demand for spider silk.

Exceptional in strength, lightness and beauty, spider web fabric is still used today and is known in China under the name “Eastern Sea Fabric”. Polynesians used the web of large web spiders as thread for sewing and weaving fishing gear. At the beginning of the 18th century in France, gloves and stockings were made from the web of crosses, which aroused universal admiration. It is known that up to 500 m of thread can be obtained from one spider at once. In 1899, they tried to obtain fabric to cover an airship from the web of a large Madagascar spider and managed to produce a sample of luxurious fabric 5 m long.

Today, spider web threads are used mainly in the optical industry for applying crosshairs in optical instruments and as threads in microsurgery, and due to their high content of bactericidal properties, they can be successfully used in medicine as suture material, artificial ligaments and tendons, films for healing wounds, burns, etc.

It is impossible to synthesize this kind of proteins in the laboratory chemically - they are too complex. However, scientists managed to create some kind of artificial analogue using biotechnological technologies. This thread was tested for strength by specialists at the Uglekhimvolokno Research Center in Mytishchi. A thread just a few microns thick can withstand 50-100 mg of load at break. It turned out to be only four times less durable than that of a spider, and this is a very good result. At the same time, the value of the rupture energy (elasticity) of this thread is already higher than that of bone or tendon.

Not only threads, but also films can be made from cobwebs. It is in this form that it is planned to use “artificial web” to make healing coverings for wounds and burns, which will not be rejected by the body and will stimulate the regeneration of its own epithelium.

Attempts have been made to obtain cobwebs naturally, similar to silk. Various devices were even invented for “milking” the spider and carefully winding the delicate threads onto a slowly rotating spool.

There were several obstacles. Firstly, the quarrelsome nature of spiders: when kept together, these animals quarrel and eat each other. Secondly, each spider produces very little web: it is estimated that 27 thousand average-sized spiders will be needed to produce 500 g of fiber. It is clear that the productivity of arthropods is unlikely to satisfy industrial demands. There is only one way out: learn to obtain it artificially.

Residents of the Pacific Islands “force” spiders to weave fishing nets that are unusually strong and almost invisible in the water. And on the island of Madagascar, located near the eastern coast of Africa, many villagers still use spider webs instead of threads.

The technology, developed about a hundred years ago by a French preacher, made it possible to collect golden webs from a million Madagascar spiders.

Art critic Simon Peers and his American business partner Nicholas Godley hired several dozen workers to create a unique canvas measuring 3.4 by 1.2 meters.

The suppliers of “threads” were a million orb-weaving spiders (golden orb spiders), belonging to the genus Nephila. The scientist and entrepreneur spent almost five years of his life and about $500 thousand to produce a piece of perhaps the most unusual fabric.

Goodley first came to Madagascar in 1994, where he created a small company producing goods from fibers of the Raphia palm tree. In 1999, Nicholas released his first collection of fashion bags (apparently from the same material), and in 2005 he closed the factory and completely switched to the production of “spider fabric” together with Pierce.

Goodley was inspired to create this unusual painting by stories about how, in the 19th century, the French governor of one of the Madagascar provinces tried to do something similar. However, Nicholas did not know for certain whether these stories were true or fiction.

In fact, spider silk is not particularly popular among the inhabitants of Madagascar (this is understandable, since the “standard” silkworm is much easier to grow). However, in the 19th century, subjects of the Merina Kingdom still decided to work with him. Products made from spider webs were presented to members of royal families. There was even a special tradition of weaving threads.

Pearce and Goodley's work began when they hired 70 workers to collect spiders of the species Nephila madagascariensis near the capital of Madagascar, Antananarivo.

Only females create a unique, durable web with a golden hue. The collection took place during the rainy season, since arthropods produce their webs only at this time of year (which imposes additional restrictions on the production process of the web).

To create a kind of spinning factory, the spiders were placed in special chambers where they were kept motionless. It must be said that Nephila madagascariensis are not poisonous, but bite. They may also escape or eat each other. “At first we had 20 females, but we soon ended up with three, but they were very fat,” says Pierce.

So, in the end, the restless creatures were isolated from each other, while simultaneously increasing the number of individuals simultaneously living in the factory.

Ten workers were collecting webs hanging from the spiders' spinning organs. In this way, it was possible to obtain about 25 meters of precious material from one individual.

Pearce notes that fourteen thousand spiders produce approximately 28 grams of spider silk, and the total weight of the final piece of fabric was as much as 1180 grams!

Next, to create the primary thread, weavers manually twisted 24 pieces of web into one, four primary ones were then turned into one main thread (a total of 96 pieces), and only from this they wove the fabric. You can imagine how painstaking the work must be.

Material from spider webs will be useful on the battlefield, in surgery and even in space, many experts are sure. The Institute of Bioorganic Chemistry of the Russian Academy of Sciences, as well as the Institute of Transplantology and Artificial Organs, are interested in obtaining products from spider web proteins.

In folk medicine there is such a recipe: to stop the bleeding, you can apply a cobweb to a wound or abrasion, carefully clearing it of insects and small twigs stuck in it. It turns out that spider webs have a hemostatic effect and accelerate the healing of damaged skin. Surgeons and transplantologists could use it as a material for suturing, strengthening implants, and even as a blank for artificial organs. Using spider webs, the mechanical properties of many materials currently used in medicine can be significantly improved.

Representatives of the arachnid order can be found everywhere. These are predators that hunt insects. They catch their prey using a web. This is a flexible and durable fiber to which flies, bees, and mosquitoes stick. How a spider weaves a web is a question often asked when looking at an amazing catching net.

What is a web?

Spiders are one of the oldest inhabitants of the planet; due to their small size and specific appearance, they are mistakenly considered insects. In fact, these are representatives of the order of arthropods. The spider's body has eight legs and two sections:

cephalothorax;
abdomen.

Unlike insects, they do not have antennae and a neck separating the head from the chest. The abdomen of an arachnid is a kind of factory for the production of cobwebs. It contains glands that produce a secretion consisting of protein enriched with alanine, which gives strength, and glycine, which is responsible for elasticity. According to the chemical formula, cobwebs are close to insect silk. Inside the glands, the secretion is in a liquid state, but when exposed to air it hardens.

Information. The silk of silkworm caterpillars and spider webs have a similar composition - 50% is fibroin protein. Scientists have found that spider thread is much stronger than caterpillar secretion. This is due to the peculiarity of fiber formation

Where does a spider's web come from?

On the abdomen of the arthropod there are outgrowths - arachnoid warts. In their upper part, the channels of the arachnoid glands open, forming threads. There are 6 types of glands that produce silk for different purposes (moving, lowering, entangling prey, storing eggs). In one species, all these organs do not occur at the same time; usually an individual has 1-4 pairs of glands.

On the surface of warts there are up to 500 spinning tubes that supply protein secretion. The spider spins its web as follows:

spider warts are pressed against the base (tree, grass, wall, etc.);
a small amount of protein adheres to the selected location;
the spider moves away, pulling the thread with its hind legs;
for the main work, long and flexible front legs are used, with their help a frame is created from dry threads;
The final stage of making the network is the formation of sticky spirals.

Thanks to the observations of scientists, it became known where the spider’s web comes from. It is produced by movable paired warts on the abdomen.

Interesting fact. The web is very light; the weight of a thread wrapping the Earth along the equator would be only 450 g.

Spider pulls thread from abdomen

How to build a fishing net

The wind is the spider's best assistant in construction. Having taken out a thin thread from the warts, the arachnid exposes it to an air flow, which carries the frozen silk over a considerable distance. This is the secret way a spider weaves a web between trees. The web easily clings to tree branches, using it as a rope, the arachnid moves from place to place.

A certain pattern can be traced in the structure of the web. Its basis is a frame of strong and thick threads arranged in the form of rays diverging from one point. Starting from the outer part, the spider creates circles, gradually moving towards the center. It is amazing that without any equipment it maintains the same distance between each circle. This part of the fibers is sticky and is where insects will get stuck.

Interesting fact. The spider eats its own web. Scientists offer two explanations for this fact - in this way, the loss of protein during the repair of the fishing net is replenished, or the spider simply drinks water hanging on the silk threads.

The complexity of the web pattern depends on the type of arachnid. Lower arthropods build simple networks, while higher ones build complex geometric patterns. It is estimated that it builds a trap of 39 radii and 39 spirals. In addition to smooth radial threads, auxiliary and catcher spirals, there are signal threads. These elements capture and transmit to the predator the vibrations of the caught prey. If a foreign object (a branch, a leaf) comes across, the little owner separates it and throws it away, then restores the net.

Large arboreal arachnids pull traps with a diameter of up to 1 m. Not only insects, but also small birds fall into them.

How long does it take a spider to weave a web?

A predator spends from half an hour to 2-3 hours to create an openwork trap for insects. Its operating time depends on weather conditions and the planned size of the network. Some species weave silk threads daily, doing it in the morning or evening, depending on their lifestyle. One of the factors determining how long it takes a spider to weave a web is its type – flat or voluminous. The flat one is the familiar version of radial threads and spirals, and the volumetric one is a trap made from a lump of fibers.

Purpose of the web

Fine nets are not only insect traps. The role of the web in the life of arachnids is much broader.

Catching prey

All spiders are predators, killing their prey with poison. Moreover, some individuals have a fragile constitution and can themselves become victims of insects, for example, wasps. To hunt, they need shelter and a trap. Sticky fibers perform this function. They entangle the prey caught in the net in a cocoon of threads and leave it until the injected enzyme brings it into a liquid state.

Arachnid silk fibers are thinner than human hair, but their specific tensile strength is comparable to steel wire.

Reproduction

During the mating period, males attach their own threads to the female's web. By striking the silk fibers rhythmically, they communicate their intentions to a potential partner. The female receiving courtship descends onto the male’s territory to mate. In some species, the female initiates the search for a partner. She secretes a thread with pheromones, thanks to which the spider finds her.

Home for posterity

Cocoons for eggs are woven from the silky web secretion. Their number, depending on the type of arthropod, is 2-1000 pieces. The females hang the web sacs with eggs in a safe place. The cocoon shell is quite strong; it consists of several layers and is impregnated with liquid secretion.

In their burrow, arachnids weave webs around the walls. This helps create a favorable microclimate and serves as protection from bad weather and natural enemies.

Moving

One of the answers to why a spider weaves a web is that it uses threads as a vehicle. To move between trees and bushes, quickly understand and fall, it needs strong fibers. To fly over long distances, spiders climb to elevated heights, release a quickly hardening web, and then with a gust of wind they fly away for several kilometers. Most often, trips are made on warm, clear days of Indian summer.

Why doesn't the spider stick to its web?

To avoid falling into its own trap, the spider makes several dry threads for movement. I know my way around the intricacies of nets perfectly, and he safely approaches the stuck prey. Usually, a safe area remains in the center of the fishing net, where the predator waits for prey.

Scientists' interest in the interaction of arachnids with their hunting traps began more than 100 years ago. Initially, it was suggested that there was a special lubricant on their paws that prevented sticking. No confirmation of the theory was ever found. Filming with a special camera the movement of the spider's legs along fibers from the frozen secretion provided an explanation for the mechanism of contact.

A spider does not stick to its web for three reasons:

many elastic hairs on its legs reduce the area of contact with the sticky spiral;
the tips of the spider's legs are covered with an oily liquid;
movement occurs in a special way.

What is the secret of the structure of the legs that helps arachnids avoid sticking? On each leg of the spider there are two supporting claws with which it clings to the surface, and one flexible claw. As it moves, it presses the threads against the flexible hairs on the foot. When the spider raises its leg, the claw straightens and the hairs push away the web.

Another explanation is the lack of direct contact between the arachnid's leg and the sticky droplets. They fall on the hairs of the foot, and then easily flow back onto the thread. Whatever theories zoologists consider, the fact remains unchanged that spiders do not become prisoners of their own sticky traps.

Other arachnids, such as mites and pseudoscorpions, can also weave webs. But their networks cannot be compared in strength and skillful weaving with the works of real masters - spiders. Modern science is not yet able to reproduce the web using a synthetic method. The technology for making spider silk remains one of the mysteries of nature.

Anyone can easily brush away cobwebs hanging between the branches of a tree or under the ceiling in the far corner of the room. But few people know that if the web had a diameter of 1 mm, it could withstand a load weighing approximately 200 kg. Steel wire of the same diameter can withstand significantly less: 30–100 kg, depending on the type of steel. Why does the web have such exceptional properties?

Some spiders spin up to seven types of threads, each of which has its own purpose. Threads can be used not only for catching prey, but also for building cocoons and parachuting (by taking off in the wind, spiders can escape from a sudden threat, and young spiders spread to new territories in this way). Each type of web is produced by special glands.

The web used to catch prey consists of several types of threads (Fig. 1): frame, radial, catcher and auxiliary. The greatest interest of scientists is the frame thread: it has both high strength and high elasticity - it is this combination of properties that is unique. Ultimate tensile strength of the spider's frame thread Araneus diadematus is 1.1–2.7. For comparison: the tensile strength of steel is 0.4–1.5 GPa, and that of human hair is 0.25 GPa. At the same time, the frame thread can stretch by 30–35%, and most metals can withstand deformation of no more than 10–20%.

Let's imagine a flying insect that hits a stretched web. In this case, the thread of the web must stretch so that the kinetic energy of the flying insect is converted into heat. If the web stored the received energy in the form of elastic deformation energy, then the insect would bounce off the web like from a trampoline. An important property of the web is that it releases a very large amount of heat during rapid stretching and subsequent contraction: the energy released per unit volume is more than 150 MJ/m 3 (steel releases 6 MJ/m 3). This allows the web to effectively dissipate the impact energy and not stretch too much when a victim is caught in it. Spider web or polymers with similar properties could be ideal materials for lightweight body armor.

So, spider web is an unusual and very promising material. What molecular mechanisms are responsible for its exceptional properties?

We are accustomed to the fact that molecules are extremely small objects. However, this is not always the case: polymers are widespread around us, which have long molecules consisting of identical or similar units. Everyone knows that the genetic information of a living organism is recorded in long DNA molecules. Everyone was holding plastic bags in their hands, consisting of long intertwined polyethylene molecules. Polymer molecules can reach enormous sizes.

For example, the mass of one human DNA molecule is about 1.9·10 12 amu. (however, this is approximately one hundred billion times more than the mass of a water molecule), the length of each molecule is several centimeters, and the total length of all human DNA molecules reaches 10 11 km.

The most important class of natural polymers are proteins; they consist of units called amino acids. Different proteins perform extremely different functions in living organisms: they control chemical reactions, are used as building materials, for protection, etc.

The scaffolding thread of the web consists of two proteins, which are called spidroins 1 and 2 (from English spider- spider). Spidroins are long molecules with masses ranging from 120,000 to 720,000 amu. The amino acid sequences of spidroins may differ from spider to spider, but all spidroins have common features. If you mentally stretch out a long spidroin molecule in a straight line and look at the sequence of amino acids, it turns out that it consists of repeating sections that are similar to each other (Fig. 2). Two types of regions alternate in the molecule: relatively hydrophilic (those that are energetically favorable to contact with water molecules) and relatively hydrophobic (those that avoid contact with water). At the ends of each molecule there are two non-repetitive hydrophilic regions, and the hydrophobic regions consist of many repeats of an amino acid called alanine.

A long molecule (eg, protein, DNA, synthetic polymer) can be thought of as a crumpled, tangled rope. Stretching it is not difficult, because the loops inside the molecule can straighten out, requiring relatively little effort. Some polymers (such as rubber) can stretch up to 500% of their original length. So the ability of spider webs (a material made of long molecules) to deform more than metals is not surprising.

Where does the strength of the web come from?

To understand this, it is important to follow the process of thread formation. Inside the spider gland, spidroins accumulate in the form of a concentrated solution. When the filament is formed, this solution leaves the gland through a narrow channel, this helps to stretch the molecules and orient them along the direction of the stretch, and the corresponding chemical changes cause the molecules to stick together. Fragments of molecules consisting of alanines join together and form an ordered structure, similar to a crystal (Fig. 3). Inside such a structure, the fragments are laid parallel to each other and linked to each other by hydrogen bonds. It is these areas, interlocked with each other, that provide the strength of the fiber. The typical size of such densely packed regions of molecules is several nanometers. The hydrophilic areas located around them turn out to be randomly coiled, similar to crumpled ropes; they can straighten out and thereby ensure the stretching of the web.

Many composite materials, such as reinforced plastics, are constructed on the same principle as the scaffolding thread: in a relatively soft and flexible matrix, which allows deformation, there are small hard areas that make the material strong. Although materials scientists have been working with similar systems for a long time, man-made composites are only beginning to approach spider webs in their properties.

Let us also note an interesting feature of the formation of the thread. The spider extends the web under the influence of its own weight, but the resulting web (thread diameter approximately 1–10 μm) can usually support a mass six times that of the spider itself. If you increase the weight of the spider by rotating it in a centrifuge, it begins to secrete a thicker and more durable, but less rigid web.

When it comes to using spider webs, the question arises of how to obtain it in industrial quantities. There are installations in the world for “milking” spiders, which pull out threads and wind them on special spools. However, this method is ineffective: to accumulate 500 g of web, 27 thousand medium-sized spiders are needed. And here bioengineering comes to the aid of researchers. Modern technologies make it possible to introduce genes encoding spider web proteins into various living organisms, such as bacteria or yeast. These genetically modified organisms become sources of artificial webs. Proteins produced by genetic engineering are called recombinant. Note that usually recombinant spidroins are much smaller than natural ones, but the structure of the molecule (alternating hydrophilic and hydrophobic regions) remains unchanged.

There is confidence that artificial web will not be inferior in properties to natural ones and will find its practical application as a durable and environmentally friendly material. In Russia, several scientific groups from various institutes are jointly studying the properties of the web. The production of recombinant spider web is carried out at the State Research Institute of Genetics and Selection of Industrial Microorganisms; the physical and chemical properties of proteins are studied at the Department of Bioengineering, Faculty of Biology, Moscow State University. M.V. Lomonosov, products from spider web proteins are formed at the Institute of Bioorganic Chemistry of the Russian Academy of Sciences, and their medical applications are studied at the Institute of Transplantology and Artificial Organs.

The abdomen of spiders contains numerous arachnoid glands. Their ducts open into tiny spinning tubes, which are located at the ends of six arachnoid warts on the spider's abdomen. The cross spider, for example, has about 500-550 such tubes. The arachnoid glands produce a liquid, viscous secretion consisting of protein. This secret has the ability to instantly harden in air. Therefore, when the protein secretion of the arachnoid glands is secreted through the spinning tubes, it hardens in the form of thin threads.

12
1. Cross spider (with an open abdominal cavity)
2. Spider arachnoid warts

The spider begins to spin its web like this: it presses the web warts to the substrate; at the same time, a small portion of the released secretion, solidifies, sticks to it. The spider then continues to pull out the viscous secretion from the web tubes using its hind legs. When it moves away from the attachment site, the rest of the secretion simply stretches into quickly hardening threads.

Spiders use webs for a variety of purposes. In the web shelter, the spider finds a favorable microclimate, where it also takes refuge from enemies and bad weather. Some spiders weave webs around the walls of their burrows. The spider weaves sticky trapping nets from its web to capture prey. Egg cocoons, in which eggs and young spiders develop, are also made from cobwebs. The web is also used by spiders for travel - small Tarzans use it to weave safety threads that protect them from falling when jumping. Depending on the purpose of use, the spider can secrete sticky or dry thread of a certain thickness.

In terms of chemical composition and physical properties, cobwebs are close to the silk of silkworms and caterpillars, only it is much stronger and more elastic: if the breaking load for caterpillar silk is 33-43 kg per 1 mm 2, then for cobwebs it is from 40 to 261 kg per mm 2 (depending on the type)!

Other arachnids, such as spider mites and pseudoscorpions, can also produce webs. However, it was spiders who achieved true mastery in weaving webs. After all, it is important not only to be able to make a web, but also to produce it in large quantities. In addition, the “loom” should be located in a place where it is more convenient to use. In pseudoscorpions and spider mites, the raw material base of the web is located... in the head, and the weaving apparatus is located on the oral appendages. In conditions of the struggle for existence, animals whose heads are weighed down with brains, and not with cobwebs, gain an advantage. That's what spiders are. The spider's abdomen is a real web factory, and the spinning devices - arachnoid warts - are formed from atrophied abdominal legs on the underside of the abdomen. And the spiders’ limbs are simply “golden” - they spin so deftly that any lacemaker would envy them.

Seeing a spider, many of us get scared and try to destroy it. And the cobwebs that hang in the corners and on the trees?
Why and how does a spider weave it?

Let's try to figure this out.
Firstly, in the abdomen of the spider there are arachnoid glands that produce a sticky secretion that hardens in the form of threads in the air, and the abdominal limbs with movable warts form a thread, and then a fiber from the threads. With the help of comb-like claws and bristles on its limbs, the spider quickly slides along the web.

Why does a spider need a web?

Like a net for catching, because they are real predators. Due to the viscous liquid, many living creatures from insects to birds get into their snare.

When a victim falls into a trap, the victim swings the web, and the vibrations transmit a signal to the spider. He approaches the trophy, sprinkles digestive enzyme, wraps it in a cocoon with a web and waits to enjoy it.

For reproduction
Male spiders knit laces next to the female’s web, then regularly knock with their limbs to lure the females for mating. And the female secretes a thread that helps find an individual for mating. He, in turn, attaches his web to the main threads and signals to his chosen one that he is here, and she, without aggression, descends along the attached web to mate.

For movement
There have been cases where spiders were seen on a ship on the high seas.

Some specimens use the web as transport. They climb onto high objects and release a sticky thread that instantly freezes in the air; and the spider flies on a cobweb with a headwind to a new place of residence.
Not very large adult spiders can rise up to 2-3 kilometers in the air and travel this way.

Like insurance
For jumpers, the web thread serves as insurance against predators and so that they can use it to attack the prey.
The South Russian tarantula always has a barely noticeable web thread stretching out to find the entrance to its burrow. If suddenly the thread breaks and he loses his house, he begins to look for a new one.
The horse can also sleep at night, thus escaping from enemies.

As a haven for posterity
To lay eggs, the female weaves a cocoon from spider web fiber, which provides security for future offspring.
The plates (main and covering) of the cocoon are woven from silk threads soaked in a frozen substance, so they are very durable, similar to parchment.
There are cocoons that are loose and look like a cotton ball.

For lining
The tarantula covers the walls of its burrows with a net so that the walls do not crumble, and builds an original mobile cover over the entrance hole.
catch prey