I suppose with brownian motion set to 10 the bots SHOUL fly around, like there is big fishes swimming around and stirring it up, but the bots moves very little. The simulation looks like there is low brownian motion. I'm not sure if I understand what this slider is supposed to do anyway, but I'm imagining that it is a calm pool with ONLY cells in it, NO big animals that stirs. That's how I want it to be.
It could be that this function isn't doing anything.