Chemotaxis is the movement of bacteria and microbes toward or away from chemicals in their environment. There are two types: positive chemotaxis involves moving toward nutrients or food, while negative chemotaxis moves away from toxins. Bacteria use chemotaxis to find food sources by sensing chemical gradients in the rhizosphere, the area around plant roots. The phenomenon was first observed microscopically in the late 1800s and research has since uncovered the mechanisms that allow bacteria like E. coli to detect chemicals and navigate chemotactic gradients. Chemotaxis plays an important role in soil bacteria finding nutrients from root exudates and forming symbiotic relationships with plants.