A comprehensive understanding is hindered by the anatomical reality that the vulva is likely not a single ecological niche, but rather a structure that includes many unique and diverse microbial habitats. The vulva consists of the mons pubis, the labia majora and minora, the clitoris, and the vestibule of the vagina. The vulvar vestibule extends laterally from the hymenal ring to a line of more keratinized skin on the labia minora. The interactions among the members of microbial populations on skin are undoubtedly important, but poorly understood. Bacterial interference is likely to be an important natural phenomenon that is helpful in understanding the forces that shape microbial populations, but this concept has also been applied in a clinical setting for infection control. The microbiota of a particular anatomical niche can play many roles, such as resisting colonization by pathogens and nutritional interactions that shape and control the population.