Why do earthworms that are underground crawl out to the surface after rain. Why do earthworms crawl out after rain? Worms come out

Many of us have seen how earthworms massively crawl out to the surface of the earth during rain, but few people know why they do it. However, scientists have a lot of interesting hypotheses. Some believe that worms are driven to the surface by the desire to travel, while others believe that the reason for this behavior is the fear of moles. There are those who consider both these hypotheses to be true.

There are many traditional explanations for this behavior of earthworms (suborder Lumbricina), but all of them are very, very doubtful. People who are far from zoology believe that worms come to the surface during rain because they love water very much and try to take advantage of the situation in order to increase the humidity inside their body. However, this version is very far from reality - after all, the moisture in the soil itself after the onset of a downpour grows quite quickly and it is enough for the worm to simply migrate from the lower layer to the "wet" upper one. But to crawl out to the surface, where it can become easy prey for predators (which, in bad weather do not doze), this creature has absolutely no need.

Biologists explain this phenomenon as follows - during rain, water penetrating the soil fills the tunnels through which earthworms move, that is, these animals do not run to the water, but from it - they are simply afraid to drown, Until recently, this hypothesis was considered the closest to the truth, although it still had one weakness. The fact is that, according to the studies of physiologists, water for worms is not as terrible as we think.

To begin with, these creatures generally feel more comfortable in conditions high humidity, because they breathe through the surface of the body, and the more damp it is around, the better oxygen passes into their body. In addition, experiments have shown that earthworms can generally live for several days in a jar of water and feel no worse than in the soil (it is interesting that almost every angler knows about this). Thus, they can calmly wait out the rain even in completely flooded "apartments" and not endanger their lives by crawling to the surface.

But why do worms do it anyway? Zoologist Christopher Lowe from the University of Central Lancashire (UK) believes that they use the rain to make long journeys. He calculated how much energy these creatures spend, crawling a distance of one meter along the surface of the earth and in the soil. It turned out that it was more profitable to crawl on the ground - it took five times less energy than when the worm squeezed between soil lumps. Well, since earthworms do not like dry air, they prefer to settle in wet weather.

However, Professor Joseph Gorris from the University of Vermont (USA) does not agree with the conclusions of his colleague. In his opinion, such behavior of worms is forced, but it is not water that makes them crawl out to the surface, but ... fear of moles! The zoologist believes that these creatures perceive the sound of rain as the approach of an underground predator, which is their enemy (contrary to what is written about the mole in fairy tales, this animal is not a vegetarian at all, but an exceptional meat-eater, and it is worms that are the basis of its diet).

Using the latest acoustic equipment, the professor found that drops falling on the surface of the earth and a mole moving underground produce very similar vibrations. It is possible that it is this similarity that deceives the worm, which is unable to determine where the source of the sound is (its hearing aid, alas, is imperfect). As a result, the animal is frightened and rushes up - although it is also dangerous there, however, the fear of the mole is stronger.

In order to test their assumption, Professor Gorris and his colleagues conducted one experiment, which, again, is known to all fishing enthusiasts. They stuck a stick into the completely dry earth, and on its top they put an iron sheet and began to shake it. The leaf immediately began to vibrate (moreover, according to the readings of the instruments, this vibration was similar to that which causes raindrops to fall on the ground), and the vibrations were transmitted through the rod to the soil. And what do you think - just a couple of minutes after the start of the experiment, worms crawled out of the ground, although there was no rain at all!

So, it is quite possible that it is crotophobia that drives earthworms to the surface of the earth. However, some zoologists believe that both Dr. Low and Professor Gorris may be right. It is possible that initially the worms crawl out because of fear of moles, and then, having figured out the situation, they decide to move to safer places. It is also quite possible that in the clusters of these animals formed on the surface of the earth, social and even marriage communications take place - partners find each other and mating occurs (since earthworms are hermaphrodites, there are no gentlemen and ladies among them, animals simply exchange sperm with each other) .

This article presents the most common and proven hypotheses. The opinions of experts and their assumptions are given. The article has Interesting Facts. The article tries to give an objective answer to the question. Earthworms, or as they are also called earthworms, are called worms that live in the earth. Their name is determined by the fact that they tend to the surface after the rains. Their length is on average from three to fifteen centimeters. But sometimes up to forty centimeters. And sometimes the length of the worms and more (up to two meters). More than a thousand species of various worms are known. Basically, worms live in the tropics. Worms feed on organic matter that decomposes.

Everyone from childhood noticed the fact that after the worms crawl out. This is what happens and has always happened. The fact will amuse many. What is the reason for this behaviour? These questions are asked by many people, as well as professional scientists and researchers of the phenomenon. The reasons for this behavior are not known. But the fact still exists.

Causes of worms crawling to the surface

Earthworms crawling to the surface - this is already a familiar picture for people since childhood. This is especially true after the recent heavy rain. There are the most different opinions and guesswork. Probably, the worms are worried about their well-being. Every inquisitive or adult breaks his head. At school, a biology course does not always cover all issues. And a school biology teacher cannot always answer the students' questions and explain the principle of the behavior of worms.

As such, there is still no clear scientific answer. Previously, it was believed that worms crawl out due to the fact that they can drown in water. Then this hypothesis was refuted, since the worms breathe through the skin. According to experts, worms are able to exist for a certain time (up to several days). But there are a number of assumptions that scientists put forward from time to time. Here are some of these hypotheses:

First guess is that the temperature of the soil changes. Worms feel it strongly. When it rains, the temperature changes by several degrees. At the depth of the earth, where worms live, the temperature is comfortable for their existence.

Second guess is to change the acid-base balance. After rainfall, the soil becomes more acidic. This causes the worms to crawl to the surface so as not to die in the changing conditions. An increase in the concentration of cadmium can also affect.

Third assumption in change weather conditions. There are worms that cannot exist in water and die accordingly.

Fourth assumption is the lack of oxygen.

There is one more point that interests observers. Why do worms get out on the asphalt? Is it a footpath or something else solid. Worms crave something solid because there is less moisture. Asphalt or concrete, which make the paths less wet. If you look closely after the rain, you can see how the worms move from the ground to the asphalt.

Which countries are participating in the study and have been successful.
The main hypotheses put forward by experts are listed above. different countries. There are some more thoughts. This may be the so-called herd instinct. Zoologists have different points of view on this issue. There are different approaches to learning.

The main successes have been achieved in the field of research by English and scientists zoologists. Different specialists adhere to different methods of study and scientific approaches. These experts are of the opinion that worms need oxygen. And from time to time, taking the opportunity to get out.

Everyone knows that the worm breathes through the skin. The worm has gills, but they are not so developed. Burrows in worms are usually about eighty centimeters. In large individuals, they can reach up to several meters. When rainwater enters the hole, the worm suffocates and crawls not down, but up (trying to escape and not die).

On the surface, those who were able to get out of the puddle remain alive, while the rest (who could not) simply die. Since oxygen is better absorbed through the surface of the skin in these conditions. There is also an opinion that worms take the sound of rain for the approach of a mole. Mole is the most main enemy for worms, which is dangerous for them. Raindrops that fall resemble the sounds of the approach of this predator. This creates an atmosphere of certain danger for the worms. They are trying to save themselves as best they can.

There are many opinions and discussions here. All worldly ideas are formed historically and passed down from generation to generation. Some even argue about it. Someone thinks that worms want more moisture (). In the earth in which worms live, moisture does not linger. Asphalt does not absorb moisture.

This explains the desire of worms. After heavy rain, you can see the movement of worms. Some of them die under the wheels of a car or under the feet of passers-by. Perhaps this version has some meaning. But someone says that they should have enough moisture in full (since there is rain in the winter and in the summer and off-season it rains). The phenomenon occurs especially after heavy rain.

Why do worms crawl to the surface? The people give their answer. folk omen, among many peoples says that this happens before the rain. Especially this opinion is held by the villagers, who are accustomed to follow nature. And you can definitely trust them. We can say that there is no unambiguous explanation of the phenomenon. There are opinions. Some of them give more understanding, and others less. At the same time, research by specialists continues and perhaps the answer will be found. And everyone will know why the worms crawl to the surface.

Copy-paste:

There are many traditional explanations for this behavior of earthworms (suborder Lumbricina), but they are all very, very doubtful. People who are far from zoology believe that worms come to the surface during rain because they love water very much and try to take advantage of the situation in order to increase the humidity inside their body. However, this version is very far from reality - after all, the moisture in the soil itself after the start of a downpour grows quite quickly and it is enough for the worm to simply migrate from the lower layer to the "wet" upper one. But there is absolutely no need for this creature to crawl out to the surface, where it can become an easy prey for predators (which do not sleep even in bad weather).

Biologists explain this phenomenon as follows - during rain, water penetrating the soil fills the tunnels through which earthworms move, that is, these animals do not run to the water, but from it - they are simply afraid to drown, Until recently, this hypothesis was considered the closest to the truth, although it still had one weak point. The fact is that, according to the studies of physiologists, water for worms is not as terrible as we think.

To begin with, these creatures generally feel more comfortable in conditions of high humidity, since they breathe through the surface of the body, and the damper it is, the better oxygen passes into their body. In addition, experiments have shown that earthworms can generally live for several days in a jar of water and feel no worse than in the soil (it is interesting that almost every angler knows about this). Thus, they can calmly wait out the rain even in completely flooded "apartments" and not endanger their lives by crawling to the surface.

But why do worms do it anyway? Zoologist Christopher Lowe from the University of Central Lancashire (UK) believes that they use the rain to make long journeys. He calculated how much energy these creatures spend, crawling a distance of one meter along the surface of the earth and in the soil. It turned out that it was more profitable to crawl on the ground - it took five times less energy than when the worm squeezed between soil lumps. Well, since earthworms do not like dry air, they prefer to settle in wet weather.

However, Professor Joseph Gorris from the University of Vermont (USA) does not agree with the conclusions of his colleague. In his opinion, such behavior of worms is forced, but it is not water that makes them crawl out to the surface, but ... fear of moles! The zoologist believes that these creatures perceive the sound of rain as the approach of an underground predator, which is their enemy (contrary to what is written about the mole in fairy tales, this animal is not a vegetarian at all, but an exceptional meat-eater, and it is worms that are the basis of its diet).

Using the latest acoustic equipment, the professor found that drops falling on the surface of the earth and a mole moving underground produce very similar vibrations. It is possible that it is this similarity that deceives the worm, which is unable to determine where the source of the sound is (its hearing aid, alas, is imperfect). As a result, the animal is frightened and rushes up - although it is also dangerous there, however, the fear of the mole is stronger.

In order to test their assumption, Professor Gorris and his colleagues conducted one experiment, which, again, is known to all fishing enthusiasts. They stuck a stick into the completely dry earth, and on its top they put an iron sheet and began to shake it. The leaf immediately began to vibrate (moreover, according to the readings of the instruments, this vibration was similar to that which causes raindrops to fall on the ground), and the vibrations were transmitted through the rod to the soil. And what do you think - just a couple of minutes after the start of the experiment, worms crawled out of the ground, although there was no rain at all!

So, it is quite possible that it is crotophobia that drives earthworms to the surface of the earth. However, some zoologists believe that both Dr. Low and Professor Gorris may be right. It is possible that initially the worms crawl out because of fear of moles, and then, having figured out the situation, they decide to move to safer places. It is also quite possible that in the clusters of these animals formed on the surface of the earth, social and even marriage communications take place - partners find each other and mating occurs (since earthworms are hermaphrodites, there are no gentlemen and ladies among them, animals simply exchange sperm with each other) .

From year to year, after rain, we can constantly observe the appearance of many hundreds of earthworms on the surface of the soil. For many of us, this fact can cause disgust, for others, indifference. However, few people think about why worms crawl out after rain?

Reasons for the appearance of worms

There is still no scientific explanation for this fact, there are only assumptions. Here are some versions.

1. Soil temperature change. Worms are very sensitive to this. The temperature of the soil during rain drops several degrees at once. After all, deep underground, where these creatures live, a fairly comfortable and warm temperature prevails for their life.
2. The change in acid-base balance is the second reason. The soil becomes more acidic after rainfall. This fact encourages them to show up on the surface in order to avoid mass death. In addition, during rain, cadmium concentrations are observed in some soils. This can also affect the behavior of earthworms.
3. Phenotypic variability of nature, that is, inconstancy. Such individuals of this species of worms appear that can die while being for a long time in water.
4. The next reason why earthworms crawl out is the lack of air, and water enriches the upper soil layer with it.
5. Another version of this animal behavior may be the “herd instinct”, when worms appear on the surface, following their relatives.
6. But still, the most simple reason lies in the relation of worms to moisture, why they were called rain worms. Zoologists believe that they appear on the surface of the earth to enjoy the water. This behavior in rainy weather is also characteristic of other animals, such as isopods.

Why do earthworms crawl out during the rains

earthworms play important role in our environment. They turn large chunks of substances into substances that can make the soil fertile. They perform this important function by pushing substances deep into the soil. Earthworms are often visible on the surface of the earth after rains. They crawl out and bend their body as if enjoying the water. Many scientists believe that several factors influence this behavior of worms after rain. These include: temperature, pH balance, as well as their natural instinct.

1. First possible cause why earthworms crawl out after rain is the change in soil temperature they feel when it rains. Most earthworms live deep underground, thanks to warm temperature under layers of soil.

2. The second possible reason why earthworms crawl out after rain is due to changes in the pH level of the soil. Other experts also believe that certain types of soil tend to receive higher concentrations of cadmium during rain.

3. The third possible answer to the question why earthworms crawl out after rain is an inconstancy, phenotypic in nature. Perhaps there are some worms that cannot submerge in water for a long time.

4. The fourth reason why earthworms crawl out after rain is the fact that some worms need little air. Water saturates the surface of the earth with a large amount of oxygen. However, P. corethrurus is a worm that can not sink in water if it does not crawl out during the rain.

5. The fifth reason why earthworms crawl out after rain is because of their natural behavior. Perhaps they crawl out after rain because most of them do that, and not because they need more or less oxygen.

6. Another possible reason why earthworms crawl out after rain is because they love moisture. Worms like to rise to the surface to enjoy the moisture on the ground. So do isopods in rainy time that climb and climb plants or trees.