Fig. 3: Learning from experience The observations show the response of the P. vortex bacteria to non lethal levels of Septrin. In (a) we show the normal growth pattern in the absence of antibiotic. The effect of first exposure of the bacteria to the antibiotic is shown in (b) and the response in a second encountered is shown in (c). In response to the antibiotic stress, the bacteria intensify chemotactic attraction to form larger vortices. This clever strategy protects the bacteria, since the antibiotic is diluted in larger vortices by the lubricating fluid excreted by the bacteria. At the same time the bacteria also enhance their repulsive chemotactic signaling to push the vortices faster away from the encountered antibiotic. The “higher complexity for better adaptability” is manifested in the fact that the growth pattern in (b) has lower complexity in comparison to that in (a). Learning from experience (c) is manifested by the fact that upon second encounter with the antibiotic the colony expands faster and the pattern has higher complexity.