Bacillus bacteria make drops of water drip to improve their spread

Rather than swimming or crawling, certain microorganisms prefer colony surfing. Using this type of movement, the bacterium Bacillus subtilis destabilizes the drops of water that contain it, by releasing surfactin. This molecule disturbs the osmotic equilibrium of the droplets and forces them to swell. As they become too heavy, they detach from their support and slide, spreading the bacterium on their way.