Lost, alone, and buffeted by ocean currents: this is the beginning of life for many oceanic larvae. These tiny organisms, often only 100 micrometers in diameter, must seek a suitable new habitat by searching over length scales thousands of times their own. But searching for something you can’t see while being dragged this way and that by ocean currents can’t be easy. How do these microscopic creatures make sense of the turbulent world around them and find their home?
No one likes being stuck. Whether you are in a car stranded in mud or stuck in a dead-end job, continuing normal behaviour is unlikely to help. Whereas we can see approaching hazards and dead-ends and try to avoid them, bacteria must blindly swim through passageways and channels that are of a similar size to themselves, often resulting in the cell becoming trapped. So, how does a bacterium change its behaviour to free itself?