Parturition, or birth, is integral to reproduction and evolutionary fitness in primates. Parturition includes labor and birth, and a postpartum phase that includes the expulsion and often consumption of the placenta. Most primates give birth to singleton offspring during the night. Parturient females usually give birth in a squatting position and primate infants are usually born in vertex occipital posterior position. Nonhuman primate neonates are more precocial than human neonates, but are still highly dependent on the care of their mothers.