The licking behavior is a gesture to show friendliness. The ancestor of dog is wolf, and wolf is a pack animal, in the pack society will be divided into ranks, according to the rank of the highland will get different treatment, but usually the dog thinks the master is its boss, think people are its leader, the dog will appear to kiss or lick behavior to show respect and obedience, just like the monkey in the monkey group, the high status will enjoy the massage and care of the low status, in the dog breed is also the same So dogs treat their masters as their superiors to lick their masters.
