Animals lick themselves and each other for many reasons, especially to keep clean. Females of some animal species, generally mammals, lick their offspring after birth to remove the baby from the amniotic sac, allowing the newborn to breathe freely. In addition to cleaning the newborn's fur, the licking contributes to the bonding between mother and baby.
Licking the newborn is one of the most evident postparturient behavior observed in female mammals. She first licks on the newborn's head, then the hindquarters, particularly near the anus. She decreases the licking after the first hour after birth. Increased levels of aggression towards approaching animals is also part of the postparturient behavior of most females.
Cleaning and Stimulating
Mammals develop inside the womb, which contains the placenta and the amniotic sac, where the embryo develops. During birth, the placenta is often expelled after the baby. However, the amniotic sac, a thin membrane that keeps the amniotic fluid and protects the fetus, often wraps around the newborn. Mothers often eat the amniotic sac's remains, while cleaning their newborns. By licking the newborn's face first, mothers make sure the baby's nostrils are clean. In addition to stimulating respiration, licking of the newborn's face also tends to stimulate a sucking response.
While licking her newborns after birth, the female is also recognizing their scent. In most mammals, the critical period for bonding between mother and newborn is the first few hours after birth. When after-birth contact between cows and their calves is delayed for five hours, the newborns have a 50 percent chance of being rejected. Sows lick their newborns less, in comparison to cows.
Checking Vital Signs
Although mammals lick their newborns more intensely in the first hours after birth, the regular licking of the offspring during the first week is also a way of checking vital signs. The mother intensifies licking when the baby does not react with sounds or movement. Among carnivores, such as lions and wolves, mothers often stop licking and eat their babies, when they are likely to be dead.