The Na’vi are monogamous creatures that mate for life. Na’vi reproduction is similar to that of placental mammals on Earth. A Na’vi female will typically produce from one to ten offspring, often spaced widely apart in time. Na’vi females have two breasts, and nurse their infants for up to four months. Some Na’vi elect to abstain from reproduction, despite being sexually active. It is not known how contraception is accomplished in this case, although the Na’vi appear to be quite sophisticated in this regard. Na’vi males are typically pair bonded with females, but male-male and female-female permanent bonds are not uncommon. Sexual activity outside of the bonded pair is not uncommon, but is almost always associated with fertility rituals and other rites, and has never been reported to lead to a disruption of the pair bond.
Though the mechanics of reproduction are similar to humans and other earth mammals, the Na’vi’s unique physiology provides them with a level of intimacy unknown on Earth. When an appropriate mate has been selected (which can take many years), the male and female Na’vi will connect queues to create an emotional bond that lasts a lifetime. The intertwining of queues, called tsaheylu, creates a state of unified body consciousness in which both parties access the physical sensations of the other. While not erotic when used for the control of animals, during mating it creates a heightened awareness of the other person. This leads to an experience similar to the prolonged state of arousal and deep spiritual connection found in some Tantric practices on Earth, but considered by the xenoanthropology community to be much more profound. A single instance of this bonding ritual leads to a life-long pair bond. The actual reproductive act, which resembles human intercourse, follows the bonding ritual, and the partners remain in a linked state during and for some time after the sex act itself.