Why do lemmings commit mass suicide?

Why do lemmings commit suicide by jumping into the sea collectively? This is a problem that local people have been puzzled. For decades, many scholars have conducted in-depth research on this natural phenomenon, trying to find out the reasons why lemmings collectively committed suicide by jumping into the sea. However, until today, there is still no convincing explanation for this problem. Summarizing people's research results, there are generally the following statements:

Lemmings committed suicide by jumping into the sea collectively, which may be related to their vigorous reproductive ability. Lemmings are not only distributed in northern Europe, but also in the northwest of America, the grasslands in southern Russia and even Mongolia. Among many lemmings families, only the lemmings in northern Europe and Norway have periodic collective jumping into the sea. Therefore, it is speculated that lemmings have lost their normal living space because of their strong reproductive ability. Too many lemmings can't get enough food and living conditions, and some lemmings have to migrate. Tens of thousands of years ago, the Norwegian Sea and the North Sea were much narrower than they are now, so lemmings at that time could swim across the sea and reach the other side. Establish a new living and residential area. In this way, the collective migration of lemmings has become the instinct of Norwegian lemmings; Generation after generation. However, as we all know, times have changed. Today's Norwegian Sea and North Sea are much wider than in the past, but the migratory instinct of Norwegian lemmings still exists.

However, this statement cannot fully explain the behavior of lemmings. For example, it has been noticed that lemmings sometimes migrate northward and jump into the Barents Sea and the Arctic Ocean. If according to the theory put forward earlier, it shows that there was land north of Barents Sea many years ago, otherwise, what is the purpose of lemmings moving north?

Not long ago, scientists in the former Soviet Union put forward a new explanation. According to the newly obtained data in recent years, they proposed that the earth was in a cold ice age 1 10,000 years ago, and the ice floes on the Arctic Ocean were frozen into thick and lasting ice sheets; The wind from the south brought a lot of sand from Siberia and North Africa to the ice sheet, thus depositing a layer of sand several meters thick on the ice sheet. Birds bring seeds of plants. Therefore, in the Arctic every summer, the ice sheet is still green and full of vitality. Mammoths, arctic yaks, arctic antelopes and many other animals suitable for cold climate can be seen everywhere, and various mice, including lemmings, may also survive on this ice sheet. Scientists have also found evidence to confirm their inference. The Liahov Islands east of Laptev Sea and some small islands on the right Mel Peninsula are made of ice. However, times have changed and the climate has changed. The huge ice sheet has disappeared and collapsed, leaving only a few small islands with clues about the ice sheet. Based on this, it is reasonable to confirm that lemmings jumping into the Barents Sea in the north are looking for the ice sheets that once existed.

Of course, those who disagree with the above views think that the above reasons are unconvincing and far-fetched. In order to further convince people, researchers need to present more substantial evidence. Some scholars believe that lemmings' collective suicide by jumping into the sea, like whale suicide, may be related to a purely unknown biological mechanism, and has nothing to do with the existence of the Arctic ice sheet.