The filament of a flagellum rotates in a kind of sinusoidal motion, resembling a ship’s propeller or a corkscrew. Since the flagellum pushes instead of pulls, it is located at the rear of the microorganism. If there is more than one, they may act as a bundle. The direction of rotation determines the path of the microorganism. Flagella also serve as sensors, particularly for the detection of moisture.
