Dogs like to lick our faces, a behavior that is disturbing for many dog owners and particularly non-dog owners. Yet, this behavior is a demonstration of friendliness, an attempt at pacifying us and themselves, a hand (though not literally) reaching for peace. It’s a compliment a dog gives you, “I like you, you can be my friend.”
The behavior originates probably in the neonatal and juvenile periods. Pups lick everything as a way of gathering information about their world. Licking our faces may give our dogs much more information about who we are and how we feel than we probably can imagine.
Pups also like to lick one another, a behavior which seems to make both donor and recipient relax because it is a pleasant and undemanding activity. Grooming and self-grooming also include licking and are again undemanding and bonding practices.
Canine mothers lick their pups, a way not only to keep them clean but also to stimulate the physiological processes of urinating, defecating and maybe even digestion.
When the pups become a bit older and begin eating solid food, it is common for them to lick the lips of the adults, a behavior which should elicit their regurgitation of recently intaken food, a good source of nutrition for the youngsters. Even though not as common as when our dogs were closer to their wild ancestors, this regurgitation behavior is still widespread among our canis lupus familiaris if we give them the opportunity to live a relatively normal dog life.
Pacifying behavior is, in general, behavior that originally performs essential functions related to survival and well-being, and that in latter stages assumes these same functions, though in different areas and with different outcomes: licking produced food regurgitation, licking produces friendly behavior.
Next time a dog licks your face, you do not need to be too terrified or disgusted. Just close your eyes, yawn, and turn your head away. This shows in dog language that you accept its offer of friendship.
By the way, don’t be too afraid either of the bacteria you may be given when your dog licks you—they are not much worse than those we get from kissing one another—and we’re not going to stop kissing, are we?
If animal behavior fascinates you, you will enjoy "Ethology—The Study of Animal Behavior in the Natural Environment," the book and course by ethologist Roger Abrantes.