TRANSITIVE PERIOD: DAY 13–DAY 20
This is when brain development quickly ramps up to bring the pup out of the neonate stage. Mentally, the change is as drastic as a caterpillar’s metamorphosis into a butterfly, or a tadpole’s transformation into a frog. It begins with the pup opening his eyes at approximately thirteen days of age, and is shortly followed by his ears opening five to ten days later.
He experiences a marked increase in brain activity during this period, showing a stark contrast with the activity of the neonate. The puppy can now crawl forward and backward, and he can finally attempt to take his first steps. He will also begin moving beyond the nesting area to eliminate without the assistance of his mother, and his interest in solid foods will increase, even though weaning won’t occur until seven to eight weeks of age.
The pup will engage in play fighting and posturing throughout the transition period. He will also begin to practice using social signals, such as growling, pawing, and tail wagging. Much to the dismay of his owner, the puppy will also exhibit signs of distress for reasons other than being cold or hungry. At this time, being separated from his littermates, being introduced to a new environment, or accidentally wandering too far from the nest will cause him to cry. Additionally, his ability to learn from training won’t reach full capacity until around four to five weeks of age.