Dogs know the reason for the owner to come back: biological clock to remind the dog’s body biological clock is very punctual, once the formation of a certain regular life, the body will soon respond. For example, the owner often take the dog out for a walk at 7 am, then the dog will generally wake up at about 7 am to wait for the owner, if the owner does not wake up, the dog may also take the initiative to call the owner to get up. If the owner comes home at a fixed time, the dog will know that the owner is coming back at this time, so start waiting at the door early. Dogs know the reason for the owner’s return: a sensitive sense of smell dog’s nose is very sensitive, it has hundreds of millions of receptor cells inside the nose, if the human sense of smell must do ordinary definition video, then the dog’s nose is ultra-high definition video. Each person will have their own unique smell, the dog’s sensitive nose can sniff out the unique smell of their master. As the owner is away from home for longer and longer, the smell of the owner at home will become more and more faint. Dogs identify the smell concentration at the moment before the owner comes home, and then the next day when this smell concentration, feel that the owner is about to return. Dogs know the reason for the owner’s return: sensitive hearing Dogs in addition to a keen sense of smell, its hearing is also very good. Dogs’ bass hearing (67Hz) is about the same as ours (64Hz), but dogs are much better than us in terms of treble. The upper limit of human hearing in high pitch is about 30,000Hz in young age, drops to 20,000Hz in the prime of life, and then drops to 12,000Hz in retirement age. According to the conclusion of several studies, the upper limit of a dog’s hearing is about 35,000 to 45,000Hz, and can even be as high as 100,000Hz. so the dog can hear the master’s voice downstairs, the master’s footsteps on the stairs, etc., so early in the doorway waiting for the master’s return.
