Ever wonder why your dog sometimes licks its muzzle for no apparent reason? If you assumed that he was just cleaning his mouth after a meal, you might be surprised to learn that he may be trying to communicate with you!

Researchers at the University of Sao Paulo (USP) and the University of Linconl, England, have concluded that licking the muzzle may be a response to the dog seeing a look of anger on humans' faces.

To this conclusion, a number of scenarios were created: dogs viewed images of other dogs and humans, both female and male, in calm and angry situations. Faces were also shown along with sound stimuli, such as pleasures or curses.

Licking the muzzle can mean a communication attempt when the dog sees you angry

Interestingly, the angry voice of humans did not have a very significant impact on dog behavior. “The licking was triggered only by visual cues (facial expressions). There was also a species effect, with more frequent licking when looking at humans than other dogs. This may indicate that this behavior is linked to the animals' perception of negative emotions, ”explains USP researcher Natalia Albuquerque.

This process must have arisen because of domestication, since the human being is usually a species with a lot of interaction and visual stimulation among themselves and among other species. Thus, as much as dogs have less keen eyesight than men, they have learned to interpret these stimuli through the perception of dissatisfaction or anger on their owners' faces.