The members of a wolf pack are familiar with each other and know each other as individuals.
They recognize each other by looks, smells, habits and behaviour.
The flock has a rank order with some individuals having a higher rank than others. A lower ranked wolf shows its inferiority with so called passive or active submission. A dominant individual marks its high rank with a cocky posture, a firm look and a raised tail.
Licking occurs also when cubs beg adult wolves for food. If a cub licks the corner of an adult's mouth, or nibbles on its nose, the adult throws up half-digested food, which the cub eats.