Why do icicles appear around the world. How and why do icicles form? Safety requirements for staying near the building and on its roof in winter

Pregnancy

There is a widespread belief that cats purr only when they feel good, expressing their pleasure and approval. This is certainly true, but there are other reasons that are less obvious and may surprise you.

Mother's purring as a source of security

When the kittens are still very small and blind, the steady purring of the mother helps them find her, calm down and feel safe. It is with these sounds that the cat makes it clear that she is friendly and ready to take care of the kittens.

Self confidence

Cats are said to purr when they feel uneasy, when they feel bad, hurt, or even before death. Purring is a kind of act of self-soothing for a cat. She associates it with positive events, so in difficult times, purring helps her feel calmer. Also, a cat can purr to relieve stress, however, if the anxiety is too great, she will not do this.

Confidence for people

Have you noticed that cats appear next to you exactly when you are upset, sick or just not in a good mood? They sit closer and start purring. By this they seem to say: “We know that you are upset, but we are with you.” It seems very touching and reminds us of how smart and sensitive our pets are.

In other cases, we can say that the cat is purring:

showing that she loves you,
enjoying food,
having a good dream
happy to meet you.

Various cat meows

1. Demanding and loud meowing

This can usually be translated from feline as “I want to eat/treat/attention, etc. right now!". The cat's body language and location will help you understand exactly what your pet needs.

2. Almost inaudible meow

In this case, your pet either wants attention or asks for something it shouldn't, like a bite of your dinner. Cats are well aware of how well their quiet purrs work, so they often get something tasty from the master's table.

3. Howl

A loud howl can indicate pain, injury, or serious distress. However, if you are convinced that everything is fine with your pets and the cat has attracted your attention in this way more than once, then you are being deceived. It is quite easy to wean her from such behavior - just do not pay attention.

4. Battle screech

Such sounds are designed to intimidate the enemy, and are made before a fight. If the opponent is not scared enough, the cat's screech will accompany the entire process of the fight.

5. Hiss

The hissing of a cat is unmistakable. It accompanies a conflict with their own kind or dissatisfaction with the actions of a person - the cat makes it clear that you should not approach her. Some experts claim that hissing is borrowed from reptiles. defense mechanism. If your cat is hissing at you, it's best to leave it alone, as there is a risk of serious scratches. Let her calm down and only then come and caress.

6. Other sounds

The list of cat “words” is almost endless. To better understand your pet, you need to listen and look closely at it, finding out in what situations and under what circumstances the cat makes certain sounds.

In any case, it is almost impossible to unambiguously answer the question why a cat makes certain sounds. The main thing to remember is that our pets are very smart little creatures, and you will get great pleasure by “solving” them.

If you have more than one cat, then you have probably noticed that even if the cats "talk" to you, they still very rarely meow at each other. The body of a cat actually expresses much more of its emotions than any sounds. So if you want to understand your pet, it is better to study his body language.

2. How to understand a cat - friction.

Rubbing a cat on any objects can mean two things: a friendly attitude or nervousness. How to distinguish?

If a cat rubs its head and muzzle against you, it means that it is glad to see you and feels safe. There are smell glands on the cat's face, so when he rubs against you, he wants to give you his scent and mark you as a member of the family (the person himself will not feel this aroma). The scent glands of cats are also located around the tail and anus. However, if the cat rubs against other parts of the body, then she is nervous and wants to determine her territory. The animal, as it were, signals: “Get out of here! This is my area!

3. When the cat "kneads" with its paws.

When a cat massages you with its front paws, accompanied by a rhythmic extension and retraction of its claws, this indicates that the animal is returning to childhood. Little kittens in this way stimulated the secretion of milk from their mother. When you see your cat in this state, no explanation is needed to understand how satisfied and happy she is.

There is an opinion that cats act in this way only if they were separated from their mother early. But it is not. Cats simply behave when they are calm and satisfied - they are full and are next to their beloved owner. If a cat begins to wrinkle your clothes (some may even suck them in) while blissfully closing his eyes, it means that he is transported back to when he was a kitten and experiences the same feeling of calm, security and pleasure. Do not deprive your pet of this pleasantness. If the cat hurts you with its claws, then put a thick blanket or towel over it and enjoy closeness and understanding with your cat.

4. How the cat's ears are placed.

The mood of a cat can also be guessed by how its ears are placed at a given moment.

A relaxed cat holds its ears slightly to the sides, as shown in Figure 1.

When the cat is interested in something and listens carefully, or is alarmed, he holds his ears straight, bringing them a little closer to each other than usual. The ears are set perpendicular to the head, slightly in front (shown in figure 2).

If the cat is upset or nervous, then he moves his ears (see figure 3). He can also hold his ears like this when exploring the territory, making sure that everything is in order.

If the cat is angry, then he presses his ears tightly to his head, holding them almost horizontally. Seeing an animal with flattened ears, it is better not to approach it, because it is ready to attack. If the ears are practically invisible, the tail twitches nervously, and the animal purrs intimidatingly, then it can pounce at any second, using its weapons - claws and teeth. Tightly pressed ears - a natural position before the attack. If the ears are not pressed tightly, then the cat is simply angry.

5. Determining the mood of a cat by the tail.

However, the most accurate indicator of a cat's feelings is perhaps its tail. By the position in which he is, you can determine the mood of the animal in this moment. It is necessary to pay attention not only to its position, but also the nature of the movements. And they can be very diverse.

The tail is raised up - this means that the animal is friendly. If a cat greets you with an upturned and trembling tail, it means that he missed you and is very happy to see you.

The tail is straight, but the cat holds it at an angle - indicates uncertainty. The cat does not feel danger, but does not fully trust the environment around him.

The tail raised up moves - the animal is in a good, playful mood, ready to play.

The tail is raised, but bent at the tip - the cat is friendly, but not quite confident.

The tail is located almost horizontally to the body, as if continuing it - the cat is not hostile, but also not afraid of you.

The tail hangs down, but is tense at the base - an aggressive animal, ready for defense.

The tail is raised, tense and slightly trembling - the cat is angry, ready to attack.

The tail hangs down - the cat can show aggression.

The tail is tucked in - the cat is submissive, humble.

The tail is raised up, trembling - the animal is glad to see you.

The cat's tail twitches along its entire length - the cat is angry and annoyed.

While the tail itself is in a state of "calm", the tip twitches - the cat is interested, ready for action.

As you can see, understanding your pet is not so difficult. Surely you yourself managed to notice many patterns in the behavior of your animal and study its habits.

What Plants Should Cats Not Eat?

A cat in the house is not only a great joy and comfort in the home, but also a number of problems that need to be addressed. Cats love to eat houseplants but some of them can be very harmful. Both at home and on the street, our pets are at risk of poisoning. What plants are tedious to protect from cats, and what harm they can bring, you will find out below.

Amaryllis is a flower that provokes vomiting and diarrhea in cats.

Azalea - a cat that has eaten this plant loses coordination, staggers and falls.

Cactus - Generally not poisonous, but puncture marks are susceptible to infections.

Caladium - Causes nausea, vomiting, diarrhea, head shaking, difficulty breathing.

Budra ivy - vomiting, diarrhea, abdominal pain, convulsions.

Ivy - vomiting, diarrhea, excessive agitation.

Lilies - cause kidney problems.

Dieffenbachia is a disorder of the central nervous system.

Mistletoe - vomiting, diarrhea, foam at the mouth, difficulty breathing.

Philodendron - nausea, vomiting, involuntary head movements, breathing problems.

Poinsettia - vomiting, diarrhea, blisters in the mouth, difficulty breathing.

Often, cats themselves feel which plant is dangerous and do not touch it. But if there are not so many plants in the house, and the animal wants to clear the stomach and eat grass, then he can take up poisonous plants. Therefore, it is advisable to supply your pet with fresh grass.

When icicles hang from the roof, they look beautiful and elegant, but they carry serious danger. Due to temperature changes, small growths and whole blocks of ice can appear hanging from the eaves of houses. They pose a threat to people passing by, as well as cars and other objects located near the walls of the building. Falling from rooftops, icicles can damage electrical wires. To prevent the appearance of icicles on cold roofs, it is necessary to organize good ventilation, and if the attic is residential, then the roof must be insulated with high quality.

Reasons for the appearance of icicles on the roof

There are several reasons that lead to the appearance of icicles on the roof of the house. Let's consider them in more detail.

How to get rid of icicles

If the causes of the appearance of icicles were not eliminated in time, sooner or later the question arises of how to get rid of them. You can cope with this task in a private house with your own hands, and to get rid of icicles on multi-storey buildings, it is best to involve specialists.

Usage modern technologies allows you to perform such work with minimal human intervention, which significantly reduces the risk of injury. But this requires the availability of specialized equipment and trained personnel. When mechanically removing ice, you must be very careful, as there is a high risk of injury or falling off the roof. In this case, you also need to have certain experience and tools.

During work on the roof of the house, you must be extremely careful and be sure to use insurance.

There are several basic options for getting rid of ice and icicles on the roof.

Equipment for removing icicles from the roof

In order to effectively deal with frost and icicles appearing on the roof big house, you need to have special equipment and tools. With their help, work will not only be easier and faster, but also safer.

To modern equipment used mainly in specialized companies include the following devices:

ultrasonic devices that destroy ice using a powerful pulse emitted in the appropriate range;
laser devices that allow you to cut icicles using a directed beam of radiation;
steam installations, in this case, icicles are cut off by a jet of steam;
chemicals that quickly dissolve ice;
electropulse installations - inductors are installed on the roof surface, which, when voltage is applied, form a magnetic field and a pulsed eddy current, due to which a short-term deformation of the roof occurs and all icicles are removed.

When carrying out mechanical removal of icicles, depending on the type of building and whether the work will be performed from the ground or from the roof of the building, the following tools will be needed:

scrapers. They have a T-shaped wooden, metal or plastic handle that is easy to pull, and at the end is a blunt metal plate;
The telescoping handle of the scraper allows you to remove snow and icicles while on the safe distance from the wall of the house
shovel. In order not to damage the coating, it is better to use a plastic or metal shovel with a rubberized blade at the end;
special axes. They also should not be sharp so that the roof of the building is not damaged during work;
ice axes. They are used to remove those icicles that are located outside the roof;
hooks and guy lines to remove large icicles. With the help of such tools, they are fixed, after which they are cut down in small parts;
stairs. It must be strong and securely installed. Instead of a ladder, you can use a hydraulic lift;
In order to reach the icicles on the roof of a tall house, you can use a hydraulic lift
long pole. With its help, you can shoot down icicles without approaching the building, and remove them at a safe distance;
hacksaw, benzo- or electric saw. These tools are used in the case of the formation of large icicles that cannot be simply knocked down;
safety equipment. If work is carried out from the roof, it is imperative to use insurance, which must be strong and reliable in order to ensure the safety of people.

Safety requirements for staying near the building and on its roof in winter

During thaws or in spring, when the snow actively melts during the day, and there are frosts at night, icicles begin to actively form on the roofs of buildings. In order not to get injured during the fall of an icicle from the roof, you must adhere to certain rules:

You need to clean the roof yourself, taking into account the following recommendations:

How to prevent the formation of icicles and frost on the roof of the house

It will be much easier and cheaper to prevent the appearance of icicles and ice than to constantly deal with them.. There are several ways to prevent the formation of ice on the roof, and which one to choose, each owner decides for himself.

The main condition under which frost will not form on the roof is to maintain a negative temperature of its surface. This is achieved by insulating the attic or under-roof space so that the heat from the house does not fall on the roofing material. In this case, the roof winter period will be covered with snow, and ice will not form on it.

The main methods for preventing the appearance of ice and icicles on the roof of a building are as follows.

Eliminate places where warm air goes to the roof. Through the ceiling, if it is poorly insulated, a lot of heat is lost, which goes to the cold attic. If there is a residential attic, then it must be insulated even more carefully, since the walls of this room are in direct contact with the roofing pie. Most often, warm air exits through gaps near the chimney pipes, at the joints of drywall boards, etc. It is easiest to determine such places in winter. It is enough to look at the roof and you will see where the snow melts more actively.
If you eliminate the places of heat loss through the roof, icicles will no longer form on it
Ensuring the required thickness of heat-insulating materials. Experts recommend that the layer of fiberglass or mineral wool be 30–35 cm. In addition to the thickness of the insulation great importance has the correct fit. Between themselves, the sheets should be tightly pressed so that there are no gaps anywhere. If the roof is properly insulated, the possibility of icicle formation will be minimized: they will appear only when the surface is warmed by the sun, but this is only for a few days.
Creation of high-quality ventilation. With the help of such a system, warm air is effectively removed to the street, and cold air takes its place. In the attic, inlets are made above the cornice, and exits are made near the ridge. In order for the ventilation system to work effectively, it must be properly calculated. If your knowledge is not enough, then it is better to seek help from specialists. total area inlet openings should slightly exceed the area of the outlet openings.
Installation of special vibrators. The vibrator can affect truss system or directly on the ice. In the first case, a small electric motor with an eccentric is installed on the rafters, which during operation creates slight oscillations with a frequency of 10–50 Hz, due to which the ice breaks and flies off the roof. Although such a device is small, it is enough to protect up to 200 m 2 of the roof. To influence the ice, equipment operating in the ultrasonic range is used. At the output of the vibrator there is an electromagnet connected to a metal circuit. When the circuit vibrates, the ice breaks. But such equipment is expensive, and besides, it is quite difficult to install.
Snow guards. These elements do not prevent the formation of icicles, but they do prevent large ice blocks from falling off the roof. They delay them, they gradually melt, and the water flows down from the roof.
Anti-lunch compounds. With their help, before the onset of cold weather, the roof is treated. These can be fluoroplastic, organosilicon compounds or a solution of synthetic rubber. After their application, the adhesion of ice and the roof is reduced, so the likelihood of ice formation is significantly reduced.
Electric heating. A special heat cable is installed on the lower edge of the roof, which does not allow ice to form. Significant funds will also have to be spent on the cable, and specialists are invited to install it. In order for the water to come down from the roof, it is necessary to do the heating of the gutters. Two types of cable can be used for the snow melting device:
- self-adjusting. It changes power depending on the temperature outside, so it may differ in different areas, which saves electricity. Such a cable does not heat up during overlaps, it is reliably protected from negative impact ultraviolet, has a high resistance to damage, it can be mounted in sections different lengths, but its cost is quite high;
- resistive. It has a constant power along its entire length, is afraid of overlaps, and also has restrictions on the maximum and minimum length but is much cheaper.
Video: installation of a roof anti-icing system
There is no one method that would completely eliminate the formation of icicles and ice on the roof. Natural factors cannot be influenced, so the snow on the roof will still melt. The implementation of the described measures will significantly reduce the rate of ice formation, so if there are icicles, they are small and unable to cause serious danger. If there is a need to clean the roof of snow and ice, then you already know how to do it yourself.

With the onset of autumn and the cooling that accompanies this process, icicles appear on the roofs of houses, on trees and other objects. Adults are accustomed to seeing them and sometimes do not even notice such a phenomenon. Children, on the other hand, show great interest in them, and sometimes they not only demand to pick a couple of pieces, but also to tell where they come from.

Icicles are beautiful a natural phenomenon, despite the fact that they can be dangerous - for example, when they hang like blocks of ice on the roofs of houses, threatening to break down at any moment. How are they formed. In fact, there are no mysteries in their appearance. Ice clusters are formed due to long-studied natural forces.

What processes form icicles?

The water on the street begins to freeze at the first negative temperatures, creating ice crusts on puddles, sleet. It freezes not only on horizontal surfaces. When flowing vertically, an ice drop can also freeze. Moreover, in many cases it flows slowly - water molecules create surface tension forces that help the drop to hold up to a certain moment on the edge of a roof, on a branch, and so on. These forces prevent the object from falling down naturally and immediately, as it should be due to the forces of gravity. A drop may well freeze while hanging, and the next drop will freeze already on it. This is how an icicle is formed - drop by drop.

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Under certain temperature conditions, which are usually observed in spring and autumn, as well as during the thaw period, snow can thaw on roofs under the rays of the sun, water drops that form during this process can roll down and gradually freeze. Subsequent drops, rolling down the already formed icing, also gradually cool down, making the icicle more and more massive and long. If frost comes again, the icicle will remain in the form in which it managed to form in warm days, and it will hang until it falls by itself due to its gravity, or is knocked down by people, by the wind. If the warming continues at an even more serious pace and the temperature rises, the icicle will melt naturally - just as it formed.

Are stalactites and stalagmites icicles?

On the arches of the caves, you can see stone stalactites, as well as stalagmites or stalagmas, which are very similar to icicles. The similarity is so clear that some people confidently consider stalactites to be ancient petrified icicles. But is it? In fact, the nature of these formations is somewhat different, although water is also “to blame” for their appearance. Seeping through the rocks earth's crust, waters often erode gypsum, limestone deposits. Water becomes hard, saturated with minerals. If such water seeps up to the vaults of the caves and begins to drip down, the process of mineral deposition begins, which forms stalactites.

The article tells about why icicles appear, how to make them yourself and what their danger lies in a big city.

Cold

On our planet there are many climatic zones. There are both hot regions and those where summer never happens, and human life is almost impossible. In some places it almost always rains, while in others it is very rare, and it is difficult for their inhabitants to imagine frequent thunderstorms, and even more so water in its non-liquid state - snow and hail.

But all cold areas and places where the temperature drops below zero during winter periods have one more familiar phenomenon in common. These are icicles. So why do icicles appear? First you need to figure it out, and ice.

Definition

According to common terminology, cooling is a phenomenon that occurs due to a decrease in temperature or the removal of heat from an object in one way or another. For most living forms low temperatures as pernicious as the high ones. And by the way, absolute cold is denoted as -273.15 degrees Celsius. Under such conditions, not only water freezes, but also metals become brittle, like glass, and the movement of elementary particles in matter practically stops.

Ice

When the temperature drops below zero degrees Celsius, water turns into ice. This is a solid state of matter, which usually has a liquid form. But if there is no rain in winter, and all the liquid freezes, then why do icicles appear on the cornices of houses? The thing is that during the winter periods the temperature can vary in a fairly wide range, and the precipitation will begin to melt, and then the new frosts will stop it. That is why the water former snow, begins to drain from the roofs of houses, and as the temperature drops, it gradually freezes, due to which the drops, sliding along the bases of icicles, do not reach the ground in full, leaving part of the liquid in the form of ice.

But sometimes in winter there is no positive temperature at all, but frost can still be observed. Why do icicles appear in this case?

Warm

In this case, house heating comes into play. According to statistics, in winter, most houses lose up to 30% of their heat through the roof, and the snow, albeit slowly, but still melts. This is especially true in private homes.

Danger

These ice formations are quite great danger. Especially in cities where there are many high-rise buildings. And all because getting to their cornices is very problematic, and icicles sometimes grow to enormous sizes. As a result, when falling, they can kill a bystander. And, let's face it, getting hit on the head with even a small piece of ice that fell from the 15th floor is a so-so pleasure.

Therefore, every winter, utilities spend a lot of effort trying to knock down icicles.

How to make an icicle?

There are several ways. The first, the most "natural". On a frosty day, you need to stock up on patience and a bottle of water. Then find an object on the street from which the liquid would drain slowly and evenly, and ideally - drop by drop. This process is not fast, but with the advent of the first ice, things will go more fun.

The second way to do it can be at any time of the year. You just need to prepare the appropriate form, pour water and place in the freezer of the refrigerator. But the main thing to remember here is that the liquid expands greatly when it freezes and can destroy the mold material, so glass is not suitable for it.

Well, the third is to get a bar and cut a narrow long cone in the form of an icicle from it. True, it will not be an icicle in the usual sense, since dry ice consists of frozen carbon dioxide, which does not melt, but evaporates. You can also get cold "burns" of the skin from it.

Now we know how icicles appear, and also learned how to make them.