Canine olfactory investigation directed towards human facial regions is a common behavior. This action allows the animal to gather detailed information via scent. The dog’s highly developed sense of smell permits the detection of subtle chemical changes emanating from the skin and breath.
This behavior serves multiple purposes. It provides the animal with data concerning an individuals emotional state, health condition, and recent activities. The collected scent data establishes and reinforces social bonds, acting as a form of greeting and recognition.