Take a look at this video of a white blood cell tracking down a staphylococcus bacterium. In more detail, here is what you are seeing in this video.
It depicts a human polymorphonuclear leukocyte (neutrophil) on a blood film, crawling among red blood cells, notable for their dark color and principally spherical shape. The neutrophil is “chasing” Staphylococcus aureus microorganisms, added to the film.
