This is a joint project with water colour artist Sarah Roberts to study the interaction of bacteria with traditional water colours. Many different types of bacteria have been assessed but only two so far, can be said to paint. When the white pigmented bacterium Proteus mirabilis, and the red Serratia marcescens are placed onto the same medium as traditional water colours, they swarm over its surface, come into contact with the paints, and then move the water colours around, in the same way that an artist might paint. Many people, including Alexander Fleming, have painted with bacteria before, but here for the first time, it is the bacteria themselves that are painting and expressing activities that would otherwise be invisible. The paintings are expressions of a microscopic reality, in which billions of invisible, mobile, and socially intelligent cells can decide whether life is getting better or worse, and decide together what to do as a response. They also reflect the latest current scientific understanding of the complexity of bacterial behaviour, how they swarm, communicate, collaborate, and build channels to irrigate large and complex bacterial communities. The “painters” also seem to possess individual character traits with Serratia marcescens making large and extravagant sweeps with the water colours. In contrast, Proteus mirabilis, appears more conservative, and makes more subtle adjustments in the arrangement of the colours. I’m no art critic, but these remind me of the Abstract Impressionism movement, with its emphasis on spontaneous and automatic creation, and created by billions of invisible Prokaryotic Pollocks.