The dots are not moving: it's a static image and there is a total of 12 dots in the picture (the illusion is more apparent in the full version of the image, below). There are twelve black dots at ...

Our brain perceives bright dots at these intersection points ... of anomalous motion illusion that gives the illusion that static images are moving like a video. Take a look at the image above ...

Moving snakes This psychedelic ... Lilac Chaser Also known as the Pac-Man illusion, this image loop shows twelve lilac dots against a gray background, with a black cross in the middle.