The period of active life of grape snails lasts from spring to the first cold days. At this time, they crawl on the surface of the ground, in trees, feed and multiply. However, as soon as the air temperature falls to 8-10 degrees Celsius, the snails prepare shelter for the winter.
Nature took care of these creatures and gave them with a set of instinctive actions so that they could save themselves from the cold weather. In addition, this process is quite interesting. Prior to it, the snail is stored with useful substances.
Snails hibernate under fallen leaves or in the pits under the ground.
Despite its slowness, shellfish are good diggers. Sometimes they pass winters even in groups, but usually choose the same place. If the soil is not too dense, they burrow to a depth of 10 to 30 cm. It depends on the severity of winter: the lower the temperature, the deeper the shelter will be.
As soon as the snail has found a suitable place, it begins to seize the head out of the ground with its wave-like movements and move it along the body to the back with wavy movements, with its foot pressed to itself. Thus, the dug soil is on top of the shell, and the mollusk continues to perform the same action, gradually penetrating deeper and covering itself with excavated soil.
Soil is very solid, and it is impossible to dig a hole. In this case, the snails spend the winter under fallen leaves. Additional protection is the epiphragm or the so called calcareous plug, which is formed from the frozen mucus of the animal and closes the shell. In this cap, the snail leaves a hole for air. Its thickness also depends on temperature.
Snails always sleep in the upstream position. It is easier for them to breathe, because there is an airflow between the membrane and the loose, excavated earth. In addition, this posture reduces the risk of penetration of bacteria from the soil and facilitates the process of going out after hibernation.
During wintering, the mollusk loses about 10% of its weight, which it manages to gain in 4-6 weeks after waking up. He wakes up quickly enough. As soon as the snow begins to melt, the mollusk goes outside so as not to drown in the formed water.
In the process of anabiosis (this is the name of the state in which snails are located during sleep) changes occur in their body: the metabolism slows down significantly, and the chemical composition of the hemolymph (the fluid that circulates in the vessels and intercellular cavities of mollusks) changes. It is dome to protect snails from the frost.
Grape snails are amazing creatures, and it is very interesting to watch their life. There are still many animals in our nature with little information known, but some facts from their existence are so unusual that it is difficult to imagine.