"Smell"
"The sense of smell is extremely totally different between dogs and folks. The share of the dog's brain that's dedicated to analyzing smells is forty times larger than that of a human! It has been calculable that dogs will determine smells somewhere between 1,000 to 10,000 times higher than humans!"
If we see some reports we will find that both humans and dogs and have similar senses seeing, hearing and smelling. Human generally makes a communication by seeing, hearing and then smelling, however, the dogs first smell and then communicate just vice-versa.
Dogs also have a special universal sense which we humans don’t have with which they can feel someone around them.