(WPF)

The anatomy and physiology of one-celled organisms are hard for us mammals to understand. It's as if the one-celled organism is living in its own stomach. It simply has to move the "food" which is essentially a duplicate of itself into a place where the digestive chemistry can do its work on the "prey." The predator becomes the dining room inside which are the digestive chemicals which digest the organism that is captured within. There is no grabbing and capturing. There is just exposing the digesting surface to the prey. The organism is essential a stomach with a "mouth." The hunter has to trap the prey so that it makes contact with digestive fluids.