Soaking in Life Soup

[Don Schaeffer]

https://www.youtube.com/watch?v=lJu0OSYbGd8
I think micro-creatures live the life of Riley, swimming leisurely about a liquid atmosphere saturated with the proteins they need. They just have to keep their digestive organs open and what they need falls in or gets pulled in or slides through their permeable bodies. Not very interesting, but they would need a brain to have interests.