Why do earthworms that are underground crawl to the surface after rain? Why do earthworms crawl out during the rains?

Why earthworms crawl out when it rains

Earthworms play an important role in our environment. They convert large chunks of substances into substances that can make the soil fertile. They do this important function, pushing substances deep into the soil. Earthworms are often visible on the surface of the earth after rains. They crawl out and bend their bodies 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 reason why earthworms crawl out after rain is the change in soil temperature they sense when rain falls. 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 a change in the pH level of the soil. Other experts also believe that certain types of soil tend to receive higher concentrations of cadmium when it rains.

3. The third probable answer to the question of why earthworms crawl out after rain is phenotypic inconstancy in nature. There may be some worms that cannot be submerged 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 big amount oxygen. However, P. corethrurus is a worm that can not drown in water unless it crawls out during rain.

5. The fifth reason why earthworms crawl out after rain is due to their natural behavior. Perhaps they crawl out after rain because that's what most of them do, 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 come to the surface to enjoy the moisture on the ground. Isopods behave the same way in rainy times, rising and climbing plants or trees.

Many of us have seen earthworms crawl en masse to the surface of the earth during rain, but few know why they do this. However, scientists have many interesting hypotheses on this matter. Some believe that the 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 of these hypotheses to be fair.

There are many traditional explanations for this behavior of earthworms (suborder Lumbricina), however, they are all very, very doubtful. People 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 humidity in the soil itself after the start of a rainstorm grows quite quickly and it is enough for the worm to simply migrate from the lower layer to the “soaked” upper layer. But crawling to the surface, where it can become easy prey for predators (which in bad weather do not sleep), this creature has absolutely no need.

Biologists explain this phenomenon as follows: during rain, water penetrating into the soil floods the tunnels through which earthworms move. That is, these animals do not run towards the water, but from it - they are simply afraid of drowning. Until recently, this hypothesis was considered the closest to the truth, although there was still one thing in it weakness. The fact is that, according to research by physiologists, water is not as dangerous for worms as we think.

Let's start with the fact that these creatures generally feel more comfortable in conditions high humidity, since 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 (interestingly, 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.

However, why do worms do this? 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 crawling on the ground was more profitable - the energy was consumed five times less than when the worm squeezed between soil lumps. Well, since earthworms do not like dry air, they prefer to settle in damp weather.

However, Professor Joseph Gorris from the University of Vermont (USA) does not agree with the conclusions of his colleague. In his opinion, this behavior of worms is forced, but it is not water that forces them to crawl 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 not able to determine where the source of the sound is (its hearing aid, alas, is imperfect). As a result, the animal gets scared and rushes upward - although it is also dangerous there, the fear of the mole turns out to be stronger.

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

So, it is quite possible that it is mole phobia 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 the worms initially crawl out of fear of moles, and then, having understood 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 mating communications occur - partners find each other and mating occurs (since earthworms are hermaphrodites, there are no gentlemen or ladies among them, the animals simply exchange sperm with each other) .

Is it true that earthworms love rain?

No, that's not true. Indeed, when it rains, worms crawl out of the ground, but of course this does not happen because they love it. Rainwater displaces air from voids in the soil. As a result, due to lack of oxygen, the worms crawl out. And the harder it rains outside, the more earthworms you can see crawling on the surface of the earth.

And from here follows the answer to another popular question - can an earthworm live in water? No, he can not. Earthworms, like humans and all animals oxygen is needed for breathing, only fish and some mammals that have adapted to being under water for a long time, such as dolphins or sharks, can live in water. Amphibians - commonly known as frogs, are distinguished here as a separate form; being born in water, they then lose their gills, and with them the ability to live only in water, although they retain a partial ability to breathe under water through their skin.

Yes, this is true, but this is why it becomes clear if you carefully study the composition of the ash.

There are three main components in ash: phosphorus, potassium and calcium. The first two fertilizers are very useful, and the last one is calcium; we commonly call this element lime. And it can be up to 80% in the ash, on average 27-30%. As you probably remember from school, and many from your own practice, our body gets burned when it comes into contact with lime. Let's not get into the point chemical reactions, just imagine the surface of the body earthworm The sensitivity of the surface of our intestines is approximately similar, imagine what will happen to the worm if it falls into the ashes - why would it love it, if only it could stay alive.

We have all repeatedly observed such a spectacle when, after a fairly heavy rain, worms appear on the asphalt or ground. Most people have long been accustomed to this phenomenon and do not attach any importance to it. special attention, however, if you are interested in why worms crawl out onto the surface of asphalt or ground after rain, information about this issue we will look at in our article today.

How do earthworms live?

The usual habitat of earthworms is the earth. Or more precisely, tunnels that worms dig under the surface of the earthen cover. It is there that they spend most of their time, since the conditions in the ground are most suitable for the habitat of this type of worm.

Like most other living organisms that live on our planet, earthworms require oxygen to function. If access to air was limited, they would simply die. And here we come exactly to the essence of the issue we are considering today.

Why do earthworms crawl out after rain?

When the amount of evaporated moisture reaches its apogee, having accumulated in the clouds above us, precipitation begins. When enough heavy rain, during showers, we have the opportunity to observe quite a large number of earthworms on the surface of the earth, on asphalt. And this phenomenon is directly related to the worms’ need for constant access to oxygen.

The fact is that when it rains, the ground is flooded with water, and the tunnels that animals have made in the soil are flooded. It should be emphasized that worms use the technique of skin respiration. Accordingly, underground the worms lose access to oxygen, and the instinct of self-preservation leads them out to the surface.

It is noteworthy that they are called “earthworms” precisely for the reason that they appear “before our eyes” precisely after rain. As for the more official and scientific name for this order annelids, then it sounds like “Earthworms.” And the etymology of this name is already quite obvious, because animals live directly in the soil, in the ground.

It is interesting to know that earthworms perform a rather important function - by creating burrows in the ground, the soil is not only better moistened, but also mixed. It is noteworthy that the average size of burrows dug by worms reaches approximately 80 centimeters, but some especially large individuals are capable of making tunnels up to 8 meters long.

It is believed that they make passages in the soil through which air and water penetrate to the roots of plants. And only relatively recently, when scientists largely established the role of worms in soil formation, they even began to be specially bred.

These animals were first linked to soil fertility in 1789 by the English naturalist Gilbert White. Charles Darwin also took up this issue and in his work “On the Formation of the Soil Layer,” published in 1831, he outlined the theory of mixing soil layers by worms.

Indeed, when worms dig their tunnels, they swallow mineral and organic components, pass them through their stomach, feed and throw them out on the other side in the form of lumps-coprolites (from the Greek words “kopros” - “dung” and “lithos” - “stone”) "). Some of these lumps can be seen on the ground around the entrances to worm burrows, and some remain underground.

And vice versa, worms come to the surface at night and take away the remains of fallen leaves and other organic matter, drag them underground and feed on them.

In the 50s of the last century, biologists conducted an experiment. Half of the light soil was poured into a box with glass walls, and the same amount of humus was poured on top. They compacted it and threw several worms into it. Within a month, passages were dug, and a lot of dark coprolite appeared in the light layer. A in three months all the soil in the box was the same color and increased in volume due to loosening.

But the main discoveries were made later. Worms not only pass the soil through themselves, but also enrich it with their unique biologically active intestinal microflora.

In addition, the tissue fluid of earthworms has cytolytic and antibacterial activity. It is impossible to list all the substances here - there are 40 types of proteins alone.

It is impossible to replace soil processed by worms with anything artificial. It creates the most for plants favorable conditions. By the way, the worms themselves, constantly being in a pathogenic, rotting environment, almost never get sick.

Scientists have been able to isolate enzymes from worm tissue that have powerful disinfecting and cleansing properties. These natural, environmentally friendly products are already used to clean pipes and apparatus in Food Industry, for washing, as detergents in hospitals, restaurants. They have also proven effective in dry cleaners for removing organic contaminants from clothing.

There are already car shampoos that easily clean the body, and especially the radiator grilles, from adhering insects. Hair shampoos and even toothpaste appeared. See it - buy it. Earthworms even began to be bred for industrial purposes on special farms.