(WPF)

Even if the water surface is relatively open, these protists tend to move into intimate groupings. Even when individuals are free to move about in search of individual interests, a high proportion of them will form groups and masses together. Is this kind of social behavior indemik? Observation suggests that a high proportion of the protist population will spend significant time massed together.

https://youtu.be/v5Bkpy23m18