What are the strange circle events of animals?

Anyone who has seen the Journey to the West must know the story of the Monkey King drawing a "forbidden circle" with a golden hoop. The Tang Priest and others sat in the circle unharmed, but the monster could not enter the circle. But this story probably originated from the "forbidden circle" of the mink bear.

In the mountains and forests of Daxing 'anling in Northeast China, there is an animal that looks like a mink and a black bear, and that is a mink bear. It has an unusual skill: whenever it is hungry, it will spread a big circle on the ground with its own urine. All the small animals trapped in the circle are enchanted, so they dare not go out of the circle and can only stay in the circle and wait for the mink to hunt. What is even more strange is that wild animals such as jackals, tigers and leopards outside the circle dare not bump into the circle. Therefore, this "forbidden circle" has the dual functions of predation and self-defense.

However, what's in the mink's urine? Why is it so amazing? This is still a mystery.

Scientists have found that from vertebrates, fish and birds to all kinds of mammals, even some invertebrates have the ability to draw circles.

Male sticklebacks usually live in groups, but their personalities change greatly during the breeding period of sticklebacks in spring. A male stickleback will drive away other male sticklebacks nearby, occupy a proper place around, become the "owner of the circle" and build a nest inside. If other male spiny fish swim near, the "circle owner" who closely monitors the boundary occupied by the circle will immediately erect the thorns on his back and meet him to fight for defending his "territory". The battle will be held near the border occupied by the circle, and the "circle master" rarely swims across the border to pursue it. However, not all fish with thorns can't get into the circle. The male stickleback in the circle only attacks the exotic male fish, while the exotic female stickleback is particularly popular. They can get along well and never attack. It is a typical "like-sex repulsion, opposite-sex attraction"!

In addition, someone once witnessed a hemp snake more than one meter long sliding along the vine. Just then, a weasel suddenly jumped out, surrounded the snake and retreated. The snake immediately stopped sliding, stayed where it was and stuck out its tongue. A few minutes later, five weasels came one after another, each with a piece of snake meat in its mouth, and roared off.

Snails also have this "special function". It is reported that a snail in the rice field drew a circle around the crab, and the crab did not move. A few days later, the crab rotted and finally became delicious for snails.

The "strange circle" of animals is vivid and interesting, and the mystery is puzzling. However, it can be seen from a large number of facts that drawing a circle is not an animal's desire for space itself, but an instinct based on the needs of life. They either draw circles to get food and ensure the stability of eating, just like mink bears; Or, like the male spiny fish, attract the opposite sex by circling, and then have children and reproduce.

In a word, animal instinct has such profound ecological value that we need to study it further in the future.