The primary function of flagella in bacteria is motility, allowing them to move toward or away from stimuli in their environment. Flagella are long, whip-like structures that rotate to propel the bacterial cell. This movement is essential for survival, enabling bacteria to find nutrients and evade harmful conditions. Additionally, flagella play a role in specialized processes like biofilm formation and adherence to surfaces. Understanding flagellar function is crucial in microbiology, particularly for developing antibiotics and understanding pathogenic behavior.