First phase

From birth, the puppy is felt and touched by his mother, he feels and touches her, he becomes familiar with her.
The prolonged absence causes distress for the puppy.
There is the beginning of reciprocal attachment, where this privileged soothing bond is woven, which allows the construction of being; for the puppy, this is as necessary for life as it is to eat and drink.

In addition to this, you need to know more about it.

Second phase

Around the 12th day, the puppy opens his eyes, sees his mother. Around the 16th day, he hears her and begins to perceive her as a distinct being
During this period, a spontaneous interaction between the puppy and its mother takes place.

Until about 4 weeks old, the puppy cannot defecate on its own. In the meantime, it is the bitch that causes the elimination of urine and excrement. To do this, she snaps her nose, turns her puppy on its side, licking the perineal region. Reflex is the puppy's first sign of submission.
Around the 5th week, the feeding becomes painful, the mother growls and pushes her puppies away with controlled teeth; the puppy tries to calm him down by putting himself on his back, resuming the posture that made her lick him for elimination.
Reassured by the proximity of his first object of attachment (his mother), the puppy can, now that he sees and hears, begin to explore the world around the nest, and try his hand at games with his siblings.

With its first acquisitions, the puppy can continue its development and socialization. Address the necessary step of the imprint to other animal species and especially to human beings, because later it will have to live and interact with them.

Hence the need, for the breeder or the family of birth, very early on to handle, touch, stroke the puppy, while respecting its fragility of course, as well as its long periods of sleep.

Then gradually, between his 3rd and 7th week, offering him the opportunity to rub shoulders with the most varied and stimulating human environment possible, will be the pledge of a good familiarization with human forms, sounds and behaviors.

During this period of strong social attraction for him, he learns by experimenting that the period of socialization is capital for the puppy, and the more the experiences will be rich and multiple for him, the more the animal will be well balanced in adulthood. .

Getting around in the car, brushing the vacuum cleaner, hearing the noises of a household full of children, teenagers, adults with screams, tears and bickering of all kinds will be of great importance to him. Hanging out with a neighbor's dog or cat, seeing a toddler on a bicycle or rollerblading swoop down on you, will not be hardships, but the everyday mundane of an average dog.

Over the course of these few weeks, the puppy will have discovered that all behavior, both his own and that of others, is an element of communication. This by experiencing the emotional state of the other, learning to discern these different states, and to influence them by adapting their own behaviors.