How do snails spend the winter? Where nudibranchs frolic

The Content Of The Article:


On the plate, snails delight demanding gourmets, while especially the nudibranch in the garden is not liked. Nevertheless, all species contribute positively to the ecosystem. They do not like cold weather, but they can not escape winter in Western Europe. Thus, nature has given them body functions that they can survive the frosty season. Instinctively, they seek a suitable place to spend the winter, where their body system goes down at appropriate winter temperatures. What the different snails do in winter is explained below.


When winter is around the corner, the numerous types of snails often react differently. While many nudibranchs die in the autumn, but still lay their eggs for the winter, others look for a sheltered place where they can not reach the frost. Hibernation usually begins in mid / late October and ends when temperatures rise again, which is usually the case in late March / early April. Then they crawl out of their hiding places and go foraging.
In most snails hibernation reduces body function significantly as soon as certain temperatures are reached that herald winter. Through this mechanism, they fall into hibernation. This makes it possible for them to become more resistant to the external cold and for the reduced organ functionality to offer less surface for freezing.


Animals, like most snail species, respond to sinking, fresh temperatures by automatically lowering their body temperature. In contrast to winter starvation, such as frogs experience in winter, these slimy animals reach a slightly higher body temperature of about five to seven degrees Celsius. In a winter stare the body temperature falls almost to 0 degrees Celsius. Exceptions include the juveniles of the Spanish slug, which belongs to the family of nudibranchs. In hibernation it can withstand frosty outside temperatures of around 0 degrees Celsius.
As a result of the body temperature reduction, there is a reduction in organ functionality. The heartbeat slows down, the breathing becomes flatter and the metabolism goes down significantly.
In contrast to the nudibranch, some snails in their less well-isolated winter quarters can also survive sub-zero temperatures above 20 degrees Celsius. For example, the snail then falls from hibernation in the winter starvation. Immobilization and a further reduction in body temperature are the result. In addition, their little houses freeze even partially.


The hibernation of these reptiles differs from hibernation, as it for example, the squirrel complies, in which no sleep interruptions due to a necessary food intake take place. While during winter hibernation, the body temperature of the animals is not reduced and therefore more energy is burned, the energy requirement of the snails decreases by about 90 percent. In order to cover the energy requirement of around ten percent in winter, they eat well in the summer so that the body can draw the required energy from the previously created fat deposits during hibernation.



The hibernation of snails is usually interrupted only when disturbed. Loud noises, the contact of the snail shell or its body by humans or other animals are examples that awaken a snail from hibernation in the short term. Here then the body temperature rises quickly and more energy is consumed. Not infrequently, this costs the hibernating animals too much energy, so that their stored fat deposits, especially in long winters, not enough and they starve to death during the winter.

Hibernation end

Although waking depends mainly on the outside temperature, other factors also play a role. If the metabolism begins to become more active again as the temperature rises, so-called metabolic end products are produced, which experts believe are serving as a kind of wake-up signal to the snails. When body temperature slowly rises again, hormone production is also stimulated. Certain hormones then take on the task of breaking down brown adipose tissue, which acted as a heat pad during hibernation. From an outside temperature of about 15 degrees Celsius, an automatic onset of muscle tremors ensures a further increase in body temperature.
Some species, such as the snail, already have an outside temperature of around eight degrees Celsius. In contrast to the nudibranch, it is less sensitive to cold and usually awakens earlier from hibernation.

winter quarters

In the choice of winter quarters, the different types of snails prefer different places to spend the winter.For example, the snail retires completely into its shell. She blocks the entrance with lime, which she can provide by her own secretion. This closure is intended to protect them from "invaders" and predators as well as from too much cold inflow while in hibernation. However, small air holes remain in the lime cover, so that a gas exchange can take place even during hibernation.
Mostly they remain in damp places, which also offer them a privacy. These include, for example:
  • In and under piles of leaves
  • Immersed in deeper burrows
  • In caves of trees
  • Under and between wooden stacks
Other types of snails, such as the land snail without snail shell, as nudibranchs are also known, are usually limited to burrows. They excavate them until they are completely in place. They also pull other parts of the plant with them and thus cushion their cave. When they are in the cave, they cover the cave entrance with earth.


In addition to freezing, dehydration also counts as a risk of dying from hibernation in the case of small, comfortable mucilaginous animals. Since she does not absorb water during the winter season and at bedtime, she otherwise has to keep her body moist. This is done by a mucus coat, which she puts on her body. This mucus layer takes some time to dry completely, then act in a manner like a cling film. However, the winter breaks in quickly and it comes quickly to a rapid drop in temperature, it may be that the mucus layer does not dry and the snail dries out after only a few days.

external threats

While the predator of snails is only man, the other snail species like the slug are exposed to several enemy objects in winter. Especially land snails without shell shelter are particularly vulnerable.


Its mucus, which moves the body and is produced in case of threats, as well as the reaction of the blood, which makes the snail's body hard and resistant, is not possible during hibernation. Although they contract and the body is a little harder, but due to the reduced energy requirements can not be made permanent condition here.
Although most nudibranchs taste cruel, the limited food supply in winter forces many an animal to eat these specimens as well. These include, for example, the marten or chickens.

Slug Control

Although they are not unimportant for the natural ecosystem, especially the nudibranchs annoy many hobby gardeners. For them, late autumn and winter are the optimal time to get rid of the annoying plant pests when cold temperatures have caused them to fall into hibernation.
The following steps should be taken to find as much as possible hibernating snail animals for disposal and then disposal elsewhere:
  • Digging vegetable patches
  • Deep hooking of earth around trees and bushes around
  • Border stored wood stacks with smooth plastic planks at the bottom about five centimeters high
  • Remove piles of leaves
  • In the early fall, water plants little to no water, so that permanent moisture is absent
Keep an eye out for any eggs, especially as the nudibranchs dig them into the ground up to about ten centimeters deep to protect them from the frost. In the spring you will have lots of little young snails in the garden, if you have not already found them in autumn and exposed them. At the surface of the earth the eggs freeze. So sometimes it is enough to turn the soil once, so that the eggs are laid out of the depths and thus exposed to the frost.
TIP: In order to prevent snails from getting into the home garden for the winter, it is advisable to stretch a special snail fence around the property at the beginning of October. However, this should be broken down at the latest in early March, so that the plant pests can out again when they are looking for food and are not sufficiently find in your garden.
As a rule, the various types of hibernate overwinter in a hibernation, and some of them can withstand frost temperatures as they fall into the winter stare.
In winter they are very frugal and quite undemanding as far as their winter quarters are concerned. They can be found everywhere, where caves, leaves, wood storage and possibly compost heap offer protection against predators and cold winter temperatures. Here you can simply collect them while you are rolling over the earth to get eggs to the surface and be destroyed by the frost. But do not forget that, for example, snails are protected by nature and should not be killed.

Video Board: .

© 2019 All Rights Reserved. When Copying Materials - The Reverse Link Is Required | Site Map