Scientists have figured out why flies don't fall from the ceiling

The obvious and the incredible surround a person everywhere. Take, for example, the situation when a fly sits on the ceiling. After all, according to the law of nature, it must fall. Or did the fly sneeze on gravity?

Scientists previously explained this discrepancy by the fact that microscopic fibers on the legs help the insect stay on the walls and ceiling. With them the fly is able to cling to the slightest irregularities.

But it turned out that the scientists were mistaken. The point is completely different. Bypass the law universal gravity The fly is helped by sticky “chewing gum” on its legs.

A microscope with a thousand-fold magnification helped to find out the “fly” secret. The fact is that on the insect’s legs there are tiny gland pads that secrete droplets of a sticky substance from a mixture of sugars and fats.

In addition to the glands, the foot has two claws that help tear it off after gluing. The force of capillary attraction of the liquid holds the fly on a smooth surface.

So the problem for an insect is not to land on the ceiling, but to break away or walk on it.

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Posted by: ascort
A more correct version of “why doesn’t a fly fall from the ceiling” was in the magazine “Inventor and Innovator”, but unfortunately I don’t remember its number. Below is the essence of this article
A fly's paw pads secrete not just a sticky liquid, but a special suspension, which, under the influence of a potential difference (nerve endings on the pads), turns into a solid substance that firmly sticks the paw to the surface. As soon as a nerve impulse is sent to lift the paw from the surface, the solid substance instantly turns back into liquid. This way the fly runs quickly and freely across the ceiling. The adhesive ability of this substance is so great that the fly is not blown away windshield car moving at high speed.

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Why do you think a fly crawls on the ceiling and does not fall? What could be causing this? small insect perform such acrobatic feats?

It used to be thought that flies are helped by the finest hairs on their legs, with which they cling to the slightest irregularities on the surface of the ceiling. But when powerful microscopes appeared, thousandfold magnification showed that the problem was not in the hairs, but in tiny gland pads that secrete droplets of a sticky substance. Just enough glue is released so that the fly has enough strength to tear its leg off the surface when needed. Its small mass helps even a thin layer of substance to hold it.

Experience with a glass

Experience : pour water into a glass, cover it with a sheet of paper (see picture), press it with your hand and carefully turn it over. Let's take our hand away. What are you observing? Why doesn't water spill?

We live at the bottom of the ocean of air. There is a huge layer of air above us. And air has weight and presses on everything below. It is the air pressure that holds the column of water in the glass. Pay attention to the shape of the surface of the paper sheet, it is concave, as if some force pressed the sheet into the glass. This is the pressure force of the air column.

It is this that helps the fly stay on the ceiling without falling. In a cat, the mass is much larger, and therefore it is not able to do this.

Experience "Magdeburg Hemispheres"

Cut out a rubber ring taking into account the internal and external diameters of the faceted glass and place it on the glass (instead, you can cut a ring from several layers of blotting paper and moisten it with water, then squeeze it lightly). Set fire to a piece of paper, lower it into a glass and almost immediately cover it with a second glass and press it against the bottom one. After 1-2 seconds the fire will go out, lift the top glass, and the top one will rise behind it. Why?

Historical reference. In 1654, Otto Guericke conducted an experiment in Magdeburg to prove the existence of atmospheric pressure. He pumped the air out of the cavity between the two metal hemispheres folded together. Atmosphere pressure the hemispheres were pressed so tightly. that they could not be torn apart by eight pairs of horses pulling in two opposite directions.

Experiment "Bottle sucking an egg"

In a bottle with a neck slightly narrower than the maximum diameter of the egg, place a burning splinter and after a while place it on the neck boiled egg. We observe: the splinter stops burning, the egg is sucked inside. The reason is that as a result of combustion, oxygen burns out, the pressure in the bottle decreases, and under the influence of the difference in atmospheric pressure and air pressure in the bottle, the egg is sucked in.

"Dry out of the water" experience

Light a candle floating in the water and, when it burns, cover it with a glass. When the candle goes out, the water is sucked into the glass and you can take the object lying in the water “dry” out of the water. Explain the result of the experiment.

Atmospheric pressure and wildlife

The existence of an atmosphere makes life itself possible on Earth and has a significant impact on its nature. Thus, atmospheric oxygen is used in the process of respiration by living organisms; plants need carbon dioxide contained in the atmosphere. Without an atmosphere, the Earth would be a lifeless desert. There would be no blue sky overhead, because it is the atmosphere that dissipates sunlight. There would be no seas and rivers, forests and wildlife. The surface of the Earth, like the surface of the Moon, would be dotted with craters, because... it is the atmosphere that protects our planet from the destructive effects of meteorites, most of which burns without reaching the Earth's surface. On Earth there would be no winds and rains, thunderstorms and sunsets, and there would be no medium in which sound could travel. The temperature during the day would exceed 130°C, and at night it would drop to -150°C.

Some birds easily tolerate areas of low atmospheric pressure and fly to high altitudes. The condor in the Andes rises to 9000 m, and nests at an altitude of 7000 m; mountain jackdaws on Everest rise to 8200 m, the vulture and hawk - to 6000-7000 m. Most birds do not rise above 4000 m.

Many living organisms (house flies, leeches, worms, fluke worms, octopuses, octopuses) have suction cups with which they can stick and attach themselves to any object: leeches move along the bottom of a reservoir, octopuses grab prey. At the same time, the suction cups increase in volume. A rarefied space is formed inside them, and external air pressure presses them against the object.

Atmospheric pressure allows animals, unlike humans, to freely pull their legs out of swampy soil. Under the leg, when a person lifts it, a rarefied space is formed and atmospheric pressure prevents the leg from being pulled out. In order to pull it out, a person must overcome not only the resistance of the soil, but also the force of atmospheric pressure. The horse has hard hooves like pistons. In pigs and ruminants, the hooves consist of several parts, and when the leg is pulled out, they compress due to the inequality of pressure above and below and allow air into the resulting depression. Therefore, there is no difference in air pressure above and below the hoof, and the leg rises easily.

Mystery experience: How to remove a coin from under the water in a plate without getting your fingers wet or pouring the water out of the plate?

Interesting phenomena related to atmospheric pressure: http://class-fizika.narod.ru/7_davlatm.htm

Conclusion

Thus, we were able to find out that this amazing ability of the insect is in fact not entirely due to the properties of its legs. It has been proven what it is physical phenomenon How atmospheric pressure plays a huge role for living organisms.

Flies absolutely don’t care what to land on: your monitor glowing in the night, your innocent nose, or the ceiling from which it will not climb down for a long time and stubbornly. Have you ever wondered, how does a fly stay on the ceiling? Of course, it is difficult to classify it as serious, but curiosity is not a vice. In contrast to the excessive intrusiveness of these insects scurrying around everywhere.

For a long time There was an opinion that numerous hairs on their paws helped them to hold on. Various irregularities on the ceiling supposedly helped these insects to cling to them with their hairs and calmly look at everything that was happening from below with truly universal calm. One could believe this: after all, perfectly smooth ceiling surfaces appeared only centuries later (read about the most popular modern ceilings for kitchen).

However, with the development of research instruments and, in particular, microscopes, the theory circulating among ordinary people was smashed to smithereens by the very first in-depth studies of the essence of an unusual issue.

It turns out that there are special glands on the legs of flies that intensively secrete a sticky substance. The pads with which flies cling produce exactly as much glue as the insect needs in order to delight numerous spectators with its presence on the ceiling. Add here its almost negligible weight - and in your mind, like a puzzle, a comprehensive answer to the question of how a fly stays on the ceiling and is practically not afraid of anything will form.

Kostenkova Anna

As a result of the experiments and studies carried out in the research work, the author concludes why m the ear does not fall from the ceiling and vertical surfaces. The work contains a lot interesting material about flies, their varieties, structure, harm and benefits to the environment.

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Research

on the topic

“Why doesn’t a fly fall from the ceiling?”

Prepared

2nd grade student

MBOU "Secondary school No. 3, Shebekino, Belgorod region"

Kostenkova Anna.

Supervisor

primary school teacher

Rubanova Oksana Viktorovna

Introduction

Research topic: “Why doesn’t a fly fall from the ceiling?”

Research problem:

These are stupid people! We don't even know

What good can a fly do?

After all, flies don’t just sit on jam.

They produce fertilizer for us.

A fly can also bring healing.

Fly for birds delicious treat.

But here’s what I don’t understand about flies:

How do flies stay on the ceiling?

Problem! I decided to reveal this secret,

Research what I don't know about.

Based on the problem raised, it was determinedpurpose of the study:

FIND OUT WHY THE FLY DOESN'T FALL FROM THE CEILING.

Objectives of our research:

• Get to know the structure of a fly;
• Observe her behavior;
• Study the experience of scientists on this topic;
• Find out what types of flies exist in nature;

Having determined the topic, problem, goals and objectives of the study, we began to put forward hypotheses. To do this, we conducted a survey among students primary school, listened to the opinions of adults, studied materials from encyclopedias and scientific publications. Thus, we have put forward the following HYPOTHESES:

• Suppose that the fly does not fall from the ceiling because its wings help it to do so.
• Let's say that a fly does not fall from the ceiling because it has special claws on its legs - hooks.
• It's possible that the insect's legs have tiny devices that secrete droplets of a sticky substance that helps it stick to the ceiling.

Initially, we decided to study in detail the structure of the fly, turning to encyclopedias about animals for help.

We learned that flies belong to:

TYPE – ARTHOPOD;

CLASS – INSECTS;

ORDER – BIWERLES.

Diptera rank first among insects in terms of numbers and diversity. About 100 thousand species are known.

The fly consists of:

Heads with large facets eyes, two antennas - these are the organs of smell, proboscis- with the help of which she feeds on liquid food.

The chest, on which there is one pair of wings for flight, and another (small) pair of wings for balance (these are the halteres).

Abdomen;

Three pairs of paws with claws.

Consider HYPOTHESIS 1 : “Suppose that a fly does not fall from the ceiling because its wings help it to do so.”

This hypothesis has NOT been confirmed. We conducted an experiment. We placed the fly in a confined space (under a transparent cup) and observed it for a while. As a result of the experiment, we were convinced that while the fly was sitting on a vertical surface or on the ceiling, its wings were motionless. Therefore, they cannot help it stay on the surface.

Consider HYPOTHESIS 2: “ Let’s say that a fly doesn’t fall from the ceiling because it has special claws on its legs—hooks.”

We carried out the proof of this hypothesis in a lesson of the extracurricular association “I am a researcher”, which I have been attending for 2 years now. Using a microscope, we carefully examined the “Fly's Foot” preparation. We saw clearlythat the insect's legs end in two claws and many hairs. Apparently these claws and hairs help them stay on various surfaces. These claws typically grip bumps on rough surfaces. They serve as support points for tiny claws.

But then we thought about the fact that not all surfaces on which a fly lands are rough. After all, there are many absolutely smooth, glossy surfaces around us. For example, glass, mirror, plastic. It is impossible for a hair or claw to catch on such a surface. But at the same time, we see that flies sit on such surfaces just as easily as on rough ones.

Thus, we came to the conclusion that 2the hypothesis was NOT CONFIRMED. Apparently it’s not the claws – the hooks.

We moved on to HYPOTHESIS 3: “It is possible that the insect’s legs have tiny devices that secrete droplets of a sticky substance that helps it stick to the ceiling.”.

To prove this hypothesis, we turned to the Internet.

The obvious and the incredible surround a person everywhere. Take, for example, the situation when a fly sits on the ceiling. After all, according to the law of nature, it must fall. Or did the fly sneeze on gravity?
Scientists previously explained this discrepancy by the fact that microscopic fibers on the legs help the insect stay on the walls and ceiling. With them the fly is able to cling to the slightest irregularities.
But it turned out that the scientists were mistaken. The point is completely different. Sticky “chewing gum” on its legs helps the fly bypass the law of universal gravitation. A microscope with a thousand-fold magnification helped scientists discover the “fly” secret. The fact is that on the insect’s legs there are tiny gland pads that secrete droplets of a sticky substance from a mixture of sugars and fats.Moreover, just enough of this sticky substance is released so that the fly can tear off its leg when walking.
A d va claw, help to tear off the fly's leg after gluing. So for an insect the problem is not to land on the ceiling, but to break away or walk on it.

Having become acquainted with this information, we once again turned to the microscope and indeed saw not only claws, but also small pads on the fly’s foot.

Then we decided to carry out the experiment proposed by British scientists.

The fly was first forced to crawl on blotting paper soaked in a fat-dissolving substance. And then they put a fly under a glass and we saw that the fly could not stay on the glass."

Thus, we came to the conclusion that 3the hypothesis was CONFIRMED.

Conclusion

As a result of the experiments and studies carried out, we can conclude that:

The fly does not fall from the ceiling and vertical surfaces becauseOn the insect's legs there are tiny gland pads that secrete droplets of a sticky substance from a mixture of sugars and fats. EJust enough of that sticky substance is released so that the fly can tear off its leg when walking. A d va claw, help to tear off the fly's leg after gluing.

During our research, we learned a lot of interesting things about flies, including the fact that flies bring many benefits, for example, they process waste, turning it into fertilizer. Or, they are able to produce bacteria that fight other pathogenic bacteria. Well, for birds, a fly is a delicacy.

Therefore, let's not forget that all living beings on this planet are part of a single ecological system of the Earth.

Application.

Types of flies

The housefly, unlike some other species, does not bite, but its presence in the house is in itself unpleasant. Some types of flies can also bite, such as horseflies. It attacks livestock (e.g.horses ), and also on people. The bites of its sharp proboscis are extremely painful. Only female horse flies drink blood. Science knows about 3,000 species of horseflies; Before mating, males often gather in flocks. Both females and males feed on the nectar of flowers, while pollinating flowering plants.
Insects use all sorts of methods of mimicry - from imitating inanimate objects to different types camouflage coloring. Another popular type of defense is imitation of poisonous and dangerous creatures.

This is what the squad members didscorpion flies- common scorpions. These inhabitants of shady, damp parks are greenish in color and have two pairs of transparent wings covered with a dark pattern. The long abdomen of the male scorpion ends in miniature pincer-like appendages, and the last segments of the abdomen itself are swollen, thrown back and painted in a bright, rich red color. You immediately recognize the “prototype” - a dangerous poisonous “tail”Scorpio . Females do not have such good mimicry: the last segments of the abdomen are not swollen, but are also colored red - bad camouflage is better than no camouflage!

Flies of the hoverfly familychose a role model among their relatives - the Hymenoptera (wasps, bees,bumblebees ). The bright yellow-black color of the wasps screams: “Don’t touch it, it will get worse, the owner is poisonous!” And that's why the birds don't touch them. There are about 4,500 species of hoverflies, or syrphid flies. Syrphid larvae are unusually diverse. The larva of the common bee lives and feeds at the bottom of reservoirs. The last three segments of her abdomen form a long (up to 15 cm!) respiratory tube. In darkness larvae living in wood of the dead trunks, special scrapers have developed from the spiracles, with which they scrape hard wood.
The larvae of many syrphids live in aphid colonies and are their fierce enemies - one adult larva can suck out 200 aphids per day. Larvae of hoverflies from the genus Microdon live in anthills and appearance completely unlike fly larvae. For a long time they were mistaken forshellfish . Bumblebee larvae live in bumblebee nests and feed on dead bumblebee larvae and waste. And adult bumblebees are very similar to bumblebees. Hoverflies can hover motionlessly in the air. They can move by sliding in air currents up, down, back, forward and sideways. Hoverflies can hover in the air for a long time, flying up to flowering plants, the nectar of which they feed on, thereby bringing benefits by pollinating flowers. They have extremely large eyes. In flight, as their name suggests, they make gurgling sounds.

Another fly chose a hard-working bee to imitate.Ilnitsa bee-eaterIt is not named so by chance: its larvae develop all summer in the silt of ponds before turning into flies in August, and an adult fly is like a bee in a pod. And not only in color, but also in behavior: it also “drags” its legs behind it when landing on a flower and taking off, as if weighed down with pollen.

Tolkuntsy They got their name because during the period of courtship with females, males in whole flocks mill about in the air. In countries with temperate climates, these dances can be seen throughout the summer. Pushing males bring gifts to females (usually small flies another species), which females eat during mating. However, males are greedy and often take their gifts from one female in order to give them to another before mating. Some even kill members of their own species in order to present them as gifts to the female. When attacking a prey, they cling to it with their strong bristly legs; In appearance, tolkuns resemble robber flies, but, unlike them, they have a rounder head.

Carrion flies can only develop inwet fell until it dried out. Therefore, their larvae: develop and grow within just a few days, this is especially noticeable in hot climates. It is not without reason that it is believed that the offspring of one pair of flies can eat a bull faster than a lion can.

There are also “honest” predators among flies. Muh-ktyrey Everyone has seen them - unattractive and long-bodied, they are colored brown and covered with hairs different lengths as if faded. Very often they warm themselves somewhere on the wall during hot hours, gaining strength before hunting. Ktyrs hunt small flies and other insects, evenspiders , which are deftly picked up on the fly right from the web. In early spring you can watch the “weddings” of ktyri: couples fly, one fly clings to the back of the other, they make circles over the clearing, as if admiring the landscape. Sometimes you see a more amazing sight: four flies fly at once, interlocking with their long legs. Just demonstration performances of aerial acrobats!

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Slide captions:

Why doesn't a fly fall from the ceiling? Research work of a student of class 2 "B" of MBOU Secondary School No. 3 Anna Kostenkova

Research problem The weather has already turned to warmth. A house fly is crawling on the glass. I just woke up from my winter sleep, New life she begins. We talk about flies without immediately thinking that a fly on its legs spreads infection. For some reason we don’t like flies from birth, and how easily we destroy defenseless flies.

Research problem These people are stupid! We don’t even know what good a fly can be. After all, flies don’t just sit on jam. They produce fertilizer for us. A fly can also bring healing. For birds, flies are a tasty treat. But here's something about flies that I don't understand: How do flies stay on the ceiling? Problem! I decided to reveal this secret, to explore what I don’t know about.

Purpose of the study: Find out why the fly does not fall from the ceiling? Objectives of the study - To get acquainted with the structure of the fly. - Observe her behavior. - Consider the experience of scientists on this topic. - Explore additional material on this topic.

The hypothesis was not confirmed Observation of a fly The wings are motionless Perhaps these are wings? Wings do not help the fly stay on the surface

What if these are claws - hooks? The hypothesis was not confirmed. Holding with the help of claws - hooks is possible only on a rough surface, and not on a glossy one.

Could it be a sticky substance? Adhesive substance: a mixture of sugar and fat. Pads - glands.

Experience of British scientists Apply a liquid that removes fat Place the fly in a confined space Transfer the fly under a clean glass The fly has difficulty climbing onto a vertical surface

Conclusion 3 hypothesis was confirmed. The fly does not fall from the ceiling because the insect’s legs have tiny pads - glands that secrete droplets of a sticky substance consisting of a mixture of sugar and fat. And the claws help the fly to tear its leg off the surface after gluing.

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