If a spider has cobwebs outside the window. How to build a nimble network. Formation of building material

Despite all the dislike of mankind for spiders, as well as the abundance of prejudices and terrible stories associated with them, the question of how a spider weaves a spider web appears in children almost simultaneously with interest, and the water is wet. The result of the labor of these unattractive animals really often resembles an elegant lace. And if the spiders themselves are unpleasant to look at, and many are even afraid of them, the web created by them involuntarily attracts attention and causes sincere admiration.

Meanwhile, not everyone knows that such "curtains" are woven by not all representatives of the detachment. Almost each species is able to create a thread for the base, but the trapping networks are weaved only by those that hunt for traps. They are called tenet. They are even isolated in a separate superfamily "Araneoidea". And the names of spiders, weaving hunting nets, totals as many as 2308 points, among which are poisonous - the same and karakurt. Those who hunt, attack from an ambush or track down prey, the web is used exclusively for domestic purposes.

Unique qualities of spider "textiles"

Despite the small size of the creators, the peculiarities of the web cause some envy on the part of the crown of nature - man. Some of its parameters are incredible even with the achievements of modern science.

1. Strength. The web can break from its weight only if the spider wicks it out 50 meters long.
2. Exceptional fineness. A separate cobweb is noticeable only when it hits a ray of light.
3. Elasticity and elasticity. The yarn is stretched without a break in 2-4 times, and without loss of strength.

And all these qualities are achieved without any technical equipment - the spider manages what nature provided it.

Types of cobwebs

It is interesting not only how the spider weaves the web, but also that it manages to produce its different "varieties". Roughly speaking, they can be divided into three types:

Scientists also distinguish another type of web, which mirrors the ultraviolet, beckoning butterflies. Many believe that the ready-made web necessarily has its own pattern. However, this is not so: the names of spiders capable of creative delights can be counted without much difficulty, and all such artists belong to the araneomorphic representatives of this detachment of arthropods.

What is it for?

If you ask a person the question of why a spider webs, he will answer without any doubts: for hunting. But this does not exhaust its functions. In addition, it is used in the following areas:

• for warming the burrows before wintering;
• to create cocoons, in which the offspring matured;
• to protect it from rain - spiders make a sort of canopy to prevent water from entering the "house";
• for traveling. Some spiders migrate themselves and are evacuated from the bosom of a family of children on long cobwebs carried away by the wind.

Formation of building material

So, let's see how the spider weaves the web. On the abdomen, the "weaver" has six glands, which are considered to be the transformed rudiments of the legs. Inside the calf, a special secret is developed, which is commonly called liquid silk. At the exit through the spinning tubes it begins to harden. One such thread is so thin that it is difficult to discern even under a microscope. Paws located closer to the "working" glands at the moment, the spider twists several threads into one spider web - in approximately the same way as women did in the old days when spinning from tow. It is at that moment, as the spider weaves the web, that the main characteristic of the future web is laid-stickiness or increased strength. And what is the mechanism of choice, the scientists have not yet figured out.

Stretching technology

The adept network for its effectiveness should be between something stretched - for example, between branches. When the first thread is created by its creator long enough, it stops spinning and spins the spinning organs. So he catches a breeze. The slightest wiggling of the wind (even from the heated earth) relates the spider web to the neighboring "support", for which it also clings. The spider on the "bridge" moves (most often sagging backwards) and begins to weave a new radial thread. Only when the base is fixed, it begins to move along the circumference, weaving into it sticky transverse lines. I must say, spiders are very economical creatures. They eat unnecessary damaged or old cobwebs, letting "recyclable" into the second round of use. And the old one becomes, according to the creator, quite quickly, since the spider weaves the spider web often every day (or night, if it is a twilight hunter).

What do spiders eat

A fundamentally important question, since the spider weaves the web, first of all, for the production of food. Note that all types of spiders, without exception, are predators. However, their diet is highly dependent on the size, methods of hunting and the place of residence. All tenet (weaving networks) spiders are insectivorous, and at the heart of their diet are predominantly flying forms. Although if a creeping character falls from the tree on a web, its owner will not disdain them. Those who live in the mink and close to the ground, eat mostly orthopterans and beetles, although they can drag into their shelter a small snail or worm. Among the variety of what spiders eat, there are also larger objects. For the water representative of the tribe with the name Argyroneta, crustaceans, aquatic insects and fish fry become the victims. Exotic giants-tarantulas hunt frogs, birds, small lizards and mice, although most of their diet is made up of all the same insects. But there are more finicky species. Individuals of the Mimetidae family hunt only for spiders that do not belong to their species. The huge tarantula Grammostola eats young snakes - and destroys them in striking amounts. Five families of spiders (in particular, Ancylometes) catch fish, and are able to dive, swim, track down prey and even pull it out on land.

In the abdominal cavity of spiders there are numerous cobweb glands. Their ducts are opened with the smallest spinning tubes, which are on the ends of six spider webs on the spider's belly. The spider-crosspiece, for example, of such tubules is about 500-550. Spider webs produce a liquid viscous secret consisting of protein. This secret has the ability to instantly solidify in the air. Therefore, when the protein secret of the spider's glands is released through the spinning tubes, it solidifies in the form of thin filaments.

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1. Spider-spider (with an open abdominal cavity)
  2. Spider web worms

The spider starts spinning its web like this: it presses the spider webs against the substrate; while a small portion of the secreted secret, solidifying, adheres to it. Then the spider continues to draw a sticky secret from the spider webs with the help of the hind legs. When it moves away from the attachment, the rest of the secret simply expands into fast-setting strands.

Spiders use cobwebs for a variety of needs. In the spider web, the spider finds a favorable microclimate, where it shelters from enemies and bad weather. Some spiders braid the web of mink walls. From the spider web spider weaves sticky hunting nets to catch prey. Egg cocoons, in which eggs and young spiders develop, are also made from cobwebs. The web is also used by spiders for travel - from it small tarzans weave safety threads that protect against falling when jumping. Depending on the purpose of use, the spider can allocate a sticky or dry thread of a certain thickness.

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

The web can be allocated and other arachnids, for example, spider mites and false-scorpions. However, the real skill in weaving the web was achieved by spiders. After all, it is important not only to be able to make a web, but also to produce it in large numbers. In addition, the "loom" should be located in the place where it is more convenient for them to use. In pseudoscorpions and spider mites, the raw material base of the web is ... in the head, and the weaving apparatus is on the oral appendages. In conditions of struggle for existence, the advantage is given to animals, whose head is heavier than brains, and not cobwebs. These are the spiders. The abdomen of the spider is a real arachnoid factory and the spinning devices - cobweb warts - are formed from atrophied abdominal legs on the underside of the abdomen. And the spiders' limbs are just "golden" - they spin so cleverly that any lacemaker can envy them.

Having seen the spider, many of us are frightened, try to destroy it. And the web that hangs in the corners, on the trees?
  Why and how does the spider weave it?

Let's try to figure this out.
  Firstly, in the spider's belly, there are cobwebs that produce a sticky secret, which solidifies in the form of strands in the air, and the abdominal limbs with moving warts form a thread, and then from filaments - fiber. With the help of crested claws and setae on the limbs, the spider quickly glides along the web.

Why do you need a spider web:

As a network for catching, because they are real predators. In their tense because of the viscous liquid many animals from insects to birds get to.

When the victim hits the trap, the victim shakes the web, and the vibrations transmit the signal to the spider. He gets to the trophy, sprinkles the digestive enzyme, wraps it in a cocoon and waits for it to be enjoyed.

For reproduction
  Spiders-males next to the cobweb of a female knit lace, then they knock with measured limbs to grind females for mating. And the female selects a thread that helps to find the individual for mating. In turn, he fastens his webs to the main strings and signals to the chosen one that he is here, that without aggression descends on a strong web to mate.

To travel
  There were cases when they saw spiders on a ship in the open sea.

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

As insurance
  For the horses, the arachnoid thread serves as an insurance against predators and to attack the victim from it.
  The South Russian tarantula always has a barely noticeable spider's thread to find the entrance to its burrow. If suddenly the thread breaks, and he lost his house, he begins to look for a new one.
  And a horse can sleep at night, thus escaping from enemies.

As a haven for posterity
  For laying eggs, the female tucks a cocoon from the arachnoid fiber, which ensures the reliability of future offspring.
  Plates (the main and covering) of the cocoon are woven from silk threads impregnated with frozen matter, so they are very strong, similar to parchment.
  There are cocoons that are loose, and look like a wadded ball.

For lining
  Tarantula covers the walls of their minks with a shadow, so that the walls do not crumble, and an original mobile cover is built on the entrance hole.
  catch prey

Most species of spiders weave a web, but not all, for example, tarantulas.  Many tarantulas burrow into the ground and release a little cobwebs, curtaining the entrance to the "cave" to make it easier to catch flying insects. All spiders, whether they weave a web or not, have several common features: they have eight legs, they all eat insects. Remember that the spiders themselves are not insects. Spiders refer to arachnids, or arachnidsare animals, in one group with which mites and scorpions enter. There are about 40 thousand species of spiders.

Why do we need a web?

They can weave very simple products, and can weave real works of art. Even when the web is ready, the spider does not settle in it forever. The spider itself can lurk under the shingles or in the corner of the window sash, or under the rock. The purpose of the web is to catch insects.  It may take several hours to weave a quality web.

How do spiders spin the web?

For example,   spider weaver  uses several types of threads to build a web. To create a framework, so to speak, the skeleton, he allocates a dry web. And in order to catch insects, the weaver puts a sticky web on the base. The spiderweb (a kind of "silk") is allocated with special glands on the spider's abdomen. Different glands secrete different types of silk. A spider can use this or that web material depending on the purpose of weaving the web.

The round spider begins to weave the web, throwing the thread into the wind. Silk flies in the wind and clings to some object, for example, over a tree branch, which allows the spider to climb up this thread and add another thread to the original to make it stronger. After the spider has made the general contours of the web, it spins a thread that connects one side of the web to the other. From the center of this connecting thread spider begins to weave another thread, which connects the center of the web with the lateral thread.

Then the spider will put a lot of connecting dry threads from the edges of the web along its radii to the center, like spokes in a bicycle wheel. Then these "spokes" are intertwined with circular threads. It turns spiral dry web. Then, a sticky thread is applied to the surface of the dry web. Now the spider gets rid of the dry web - it eats it. The fishing gear is made, the insect snares are ready.

Interesting fact:some cobwebs can be more difficult, others are easier.

Web design

The design of the web, according to experts, varies depending on the method of hunting. For us, the entire web seems to be the same and consists of completely standard elements. Such a deceptive impression is created because we do not see the web in the ultraviolet light.

Why does the web attract insects?

Ultraviolet rays are an integral part of sunlight, and it is that part that forms the tan of the skin. But the frequency of ultraviolet waves is too high and not perceived by our eyes, so for us this is an invisible light. However, many insects are able to see ultraviolet rays, especially those that feed on flower nectar and pollen. Many spiders weave a web that attracts these insects. How it's done? First the spider weaves a web of threads, which almost do not reflect ultraviolet rays. Then he weaves into the web design a thread of another type that shines brightly in the ultraviolet rays.

What is the point in this design? According to many researchers, the shape of the filament, reflecting ultraviolet rays, is similar to the shape of flowers, also reflecting these rays. The insect, very hungry, is looking for something to eat. And suddenly ahead it sees a coveted flower sparkling with ultraviolet rays. The insect flies to the flower and enters the net, where a no less hungry spider waits long.

Today I answer the question of Alena's mom: " As a spider weaves a web among the trees?"

On Earth there are more than 20 thousand species of spiders! There are among them quite innocuous, but there are poisonous ones (for example, the Karakurt, which lives in Crimea). There are quite small (spiders of the species Patu digua) - with the size of the abdomen 0.37 mm, and there are huge (spiders-bird-eaters) with the size of the abdomen 9 cm, and if with the legs, it's all 20-25 cm. There are discreet: black or brown (for example, often living in our houses haymaking or wolf-spiders), but there are brightly colored - with colored strips (like Arjopi Bryunnich) or some patterns (for example, in spider-spiders the spots on the back form a cross). Most species are overland, but there are also living under water (water spiders). But all of them are united by the fact that all of them, without exception, weave cobwebs.

Any spider on the bottom of the abdomen has so-called spider web warts, from which a spider's fluid is released. The liquid quickly freezes in the air, turning into strong threads. I think your child has ever seen how hot-melt glue (or other fast-setting glue) glues: how the tube stretches and then a thin thread stiffens in the air. ( If there is such an opportunity - give the baby such a glue, let him try to make a "spiderweb"). That's exactly how a spider web spins.
  Why she sticks, we dismantled in a separate issue of the "Club of the Crows": " Why is the web sticky? ".
  But the web is not only sticky, it is also very strong. It's hard for a child to believe in this - he knows from experience how easy it is to tear a spider web. But ask him to imagine that if we could get a web as thick as a wire, then it would be two to three times stronger than a wire!

Task 1. What would have happened if ... (elements of TRIZ)

Fantasize, what would happen if the spiders were able to spin such a thick web? Dangerous or useful would it be for people? And how would people use it?

External structure of the spider

  If you ask a baby why a spider needs a web, it is likely that the spider will use it to catch insects. This is the most famous purpose of cobwebs. But does the kid know that the spider web is needed by spiders for so many more things? For example, there are species of spiders (the so-called stray spiders) who prey on prey without weaving the net, but catching up with the insect and attacking it. And then they wind it with a cobweb to bring it to their lair. For them, the web is like ropes  for binding. Many kinds of spiders cover the cobweb of the wall and the floor of their home - for them the web serves as a soft carpet. The water spider weaves the web under the water so that it holds the air bubbles that it collects under it, creating itself a reserve for breathing. Web for him at the same time and pantry  and a network for a peculiar balloon. Female spiders weave from the web cocoons  and lay eggs in them, from which the spiders then hatch. For them, cobwebs are cradles. And for many people spider webs - this parachute. Did the kid notice that in the beginning of autumn, in the so-called "Indian summer", many silvery spiders fly through the air? If you look closely, he can see that behind the tip of each is a tiny spider. This newly hatched spider is resettled from its nest. After all, at one time they are born in different species from a dozen to a hundred, so they live closely together. Here spiders and use a spider web as a parachute, so that the wind carries them to the far edges.

But, of course, with the word "cobweb" we first of all seem to be beautiful circular networkstretched between trees or in an abandoned corner of the house. Such networks basically weave different kinds of spiders-crosses.

A spider-web spider. Photo from Wikipedia

How do they weave the web so that their threads are stretched between the supports?Sometimes even a considerable distance. Did you notice that in the forest the web sometimes happens to be stretched across the path, fastening on the trees on its opposite sides? They do this as follows. The spider releases a long string. With a favorable combination of circumstances, the air stream picks up this spider web, and it hooks on the branches of the nearby tree (1-2). And then everything is simple and magical: after moving to the middle of this auxiliary thread, the spider weaves another freely hanging thread, then moves to its middle and, hanging vertically down, spins another spider web, until it reaches some support (3). This is the basis for the skeleton in the form of the letter Y. (Does the little one know this letter of the English alphabet? The word "yellow" - "yellow" begins with it.) What letter does it look like? Is it possible for him to find a wand in the form of the letter "Y" "?).
  Then witchcraft begins: the spider connects the point of intersection of the spider web with several radii (4). And on them he weaves an auxiliary spiral, moving from the center (5).

While all the threads that he wove, made of non-sticky cobweb. By the way, this is the secret of the fact that spiders never stick to their network - they run only along these threads, underlying the web. And, reaching the edge, he begins to weave a second spiral (from the edge to the middle) already using a sticky web (6).

  Do you see how difficult? But this is not the most surprising. Surprisingly, the web of spider-crawlers always has the same geometric structure. The first spiral has few turns and the distance between them increases with each circle. As a result, he has a curved line. which is called logarithmic spiral. (For a kid to understand this name, it is enough to tell him that a logarithm is a word from mathematics.) There is an "addition", there is a "subtraction", and sometimes a "logarithm." He will teach it in school). But the coils of the second, sticky, spiral are located among themselves always at the same distance. This spiral is called archimedean, in honor of the great ancient Greek scientist Archimedes. Here's what, it turns out, the spider is a good mathematician!

Task 2. Determine the type of spirals.

Ask the baby among the other curves in the figure to find all the spirals. Which of them are logarithmic, and which Archimedean?

Task 3. We prepare a hand for writing.

And now offer the little guy to weave a spider web. To do this, you need to save to your computer and print out the below picture-prescriptions (only open them in a new window, right-click on the picture and select "Open in new tab" - then the images will open in full size).

  But the spider webs are also of a different kind.
  For example, spiders of the genus Argiope adorn their networks zigzag patterns, woven into the main threads of the web. These patterns are particularly well visible in ultraviolet light, which attracts insects, since usually they see all sorts of sweet fruits in the ultraviolet, etc.

The Argiope Web. Photo from Wikipedia

  Spiders of the family Dinopidae spinosa weave small mesh  between their legs and throw it on the insect running under them.

Funnel spiders weave mesh waste basket  and hide in an ambush on her bottom.

Spiders Mastophora weave only a few threads and hunt, sitting on them. They swing one of the threads with a sticky droplet on the end and ambush it like a lasso  to his sacrifice.
  Mink spiders hide in their burrow, pre-stretched around it signal strings. They attack the prey as soon as she touches one of those strands.

And there are spiders that weave a huge chaotic web. The most notable of them are Uloborus republicanus ("public") spiders - they are working together to weave a common network that sometimes reaches a giant scale.
  well and the largest web in the world  was discovered in 2007 in the national park of Lake Tawakoni (USA, Texas). Its size is 180 meters! They made her spiders of several different species, which usually do not cooperate, but even are at enmity with each other.

The giant web in Texas. Photo from blogga.ru

Task 4. We play!

And your baby wants to build a giant cobweb? Give him a spool of threads and suggest pulling them between all the objects in the room (just take care that he does not attach the threads to objects that can fall). And then, when the catching net is ready, play with it in a spider and fly, arranging catch-ups with obstacles among these threads.

Playing the web

Task 5. Spirograph.

It was fun? To calm down and take a little breath, invite the kid to draw his colorful patterns for the web. You can draw them out of your head. And you can apply for this special line - spirograph. With its help you get very interesting pictures. But in order to make them, the kid will need patience and skillful fingers. Circle after circle, like a spider weaves a web, we must weave patterns, rotating spur gears of a spirograph.

Patterns on a spirograph

Task 6. The basics of English.

And at last you can learn together with the kid a funny English poem about a spider (the page is taken from my