The dog knows the reason why the owner is coming back: Biological clock reminder

The biological clock in the dog's body is very punctual. Once a certain regular life is established, the body will respond quickly. For example, if the owner often takes the dog out for a walk at 7 o'clock in the morning, the dog will usually wake up and wait for the owner around 7 o'clock. If the owner does not wake up, the dog may take the initiative to wake up the owner. If the time when the owner comes home is roughly fixed, as time goes by, the dog will know that the owner is coming back at this time, so he will start waiting at the door early.

The reason why the dog knows the owner is back: Sensitive sense of smell

The dog’s nose is very sensitive. There are hundreds of millions of receptor cells in the nose. If the human sense of smell is considered to be of ordinary clarity, The video of the dog’s nose is an ultra-high-definition video. Everyone has their own unique smell, and a dog’s sensitive nose can smell out the smell that belongs to his or her owner. As the owner leaves home for longer and longer, the smell of the owner in the home will become weaker and weaker. The dog recognizes the odor concentration at the moment before the owner comes home, and then feels that the owner is coming back at this odor concentration the next day.

The dog knows the reason why the owner is back: sensitive hearing

In addition to a sensitive sense of smell, dogs also have excellent hearing. Dogs’ bass hearing (67Hz) is about the same as ours (64Hz), but dogs are much better than us at treble. The upper limit of treble that humans can hear when they are young is about 30,000 Hz, which drops to 20,000 Hz in their prime, and to 12,000 Hz in their retirement age. According to data from multiple studies, the upper limit of a dog’s hearing is approximately 35,000 to 45,000 Hz, or even as high as 100,000 Hz. Therefore, the dog can hear the owner's voice downstairs and the owner's footsteps going up the stairs at home, so it can wait for the owner's return at the door early.