I don't know if the pet owner has noticed that when the dog is in a dark silence or walking on a narrow road, the dog will slightly tremble its beard. I think the reason why dogs do that is to check the width of the road surface, which is conducive to accurately and randomly acting and preventing them from getting stuck in a certain place and unable to move.
The dog's beard has the effect of radar detection, can identify and recognize the existence of objects, and help dogs discover the overall target. For example, falling dog food, snacks or other subtle items, dogs can find them based on their beards. Because there are many nervous systems gathered at the root of the dog's beard, no matter what the dog's beard encounters, it can be passed on to the dog's memory.
People understand that a dog's beard is under the eyes. I think that it can protect the dog's eyes. Why do you say that? Because when the dog's beard touches other items such as soil, grass, etc., the dog will blink, and then determine whether it is too close to its eyes to prevent it from poking.
I think the key function of beard is to help dogs' eyesight. Because the beard can recognize the mild fluidity of the gas, its slight changes in wind frequency and wind power, this will make the dog think about the existence of hunting or other surrounding objects, as well as their size and body shape, which can make the dog hunt stronger.