Dogs sniff human genital areas primarily because these regions have a high concentration of apocrine sweat glands that release pheromones and other chemical signals. These scents convey information about a person’s age, sex, mood, health, and even recent activities like sexual intercourse or menstruation. Dogs have an incredibly sensitive sense of smell-far superior to humans-and use sniffing as a way to gather detailed information, much like how they greet and learn about other dogs by sniffing their rear ends. This behavior is instinctual and serves as a form of social investigation or greeting in the canine world.