How swimming bacteria spin fluid

In today’s study, Dunkel and his colleagues investigate how bacteria can make flow patterns that look turbulent -  chaotic and full of vortices - even though bacteria are tiny and slow.  The bacteria push the fluid around as they swim and create vortices, spinning regions in the fluid. The 5 μm long bacteria create vortices with diameters of 80 μm by swimming at the speed of 30 μm/s!