People walk in the dark suburbs, it is easy to go out of a large circle and return to the original place, folk call this phenomenon "ghost hitting the wall". Is there really a ghost that can't be played? This is certainly not possible.
In fact, not only people, but also animals. For example, blindfolded chickens run in circles, blind birds fly in circles, and blinded dogs swim in circles in the water. Why is this happening.
Scientists believe that the movement of circles is a basic movement. For example, tightly wound toy cars run on the ground and rarely run in straight lines, either in arc or in circles. If you want the trolley to drive in a straight line, the wheels on both sides of the trolley must be absolutely balanced, and the uneven ground must be eliminated. The same is true of people walking in circles in pitch-black environments.
In general, people walking during the day or in a familiar environment will pay attention to their own footsteps and adjust the direction at any time with their own sensory organs. However, if you walk in a dark and unfamiliar environment, it can become difficult even if you want to walk in a straight line. Not to mention that there is always a slight difference between a person's legs (differences in bones, muscles, etc.), even if the human body is completely symmetrical, it is obviously impossible to take every step at the absolute same distance.
![Have you ever heard of "ghosts hitting the wall"?[fig]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)