Animal of the week: In a wild experiment, mice multiplied until they could no longer live

Us will soon be 8.3 billion. The population of the earth will increase by billions, but according to the forecasts starts to turn into a decline in the year 2100.

A general concern has been the earth’s carrying capacity, but Elon Musk has, on the contrary, feared a “population collapse”. When space should also be populated in the future.

The buzzword in the 1960s was population explosion. In the atmosphere of that time, a wild mouse experiment was conducted, from which they tried to draw parallels to the future of the human species as well.

Behavioral scientist John B. Calhoun built a city for mice the size of a small room where they had no shortage of anything.

In Calhoun’s utopia, the mice had unlimited water and food, comfortably warm, a big playground full of exercise chips, their own rooms, and no fear of predators. He wanted to see what was going on.

Four couples moved in as the first residents of Hiirikaupungi in July 1968. In the beginning, the population grew explosively. The number of mice doubled every two months until there were 2,200.

Utopia turned into hell. Although the mice still had unlimited food, there were simply too many of them. The social order collapsed, if you can talk about that in the case of mice.

The young males fought with each other, the mothers couldn’t take care of their chicks, some of the mice retreated to their own conditions on the upper floors of the structure to sleep and rest like some reclusive millionaire.

The mice could no longer even eat without the company of others. Eventually they forgot how to multiply. The last chick was born in March 1970.

This started a collapse that ended with the death of the last mouse in 1973. So the whole city simply died out.

Calhoun’s original research article “Death Squared” (death to the power of two) appeared in the same year.

About research still see colorful interpretations on the internet. How social media and constant presence changes us, how the bustle of big cities makes us indifferent, and so on.

Actually, the mouse experiment didn’t say anything about human behavior. It just told what happens when mice are forced into conditions that are not typical for them. No more such things would be done.