Why Na'vi Have Breasts Because director James Cameron milks audience lust By Mary Papenfuss, Newser User Posted Feb 25, 2010 5:12 AM CST 19 comments Comments Is Jake trying to figure out why Neytiri has breasts? (AP Photo/20th Century Fox) (Newser) – OK, they're small, but Na'vi women definitely have them: Breasts. But why? They're extraterrestrials, not mammals, who don't need them to nurse their babies. So why are they there? Simple. "Because this is a movie for human people," director James Cameron explained in an Inside the Actors Studio interview. He aimed to create a different kind of creature who was also seductive, and he had a definite vision regarding star Neytiri. The Na'vi are not "placental mammals," Cameron explained to Playboy. But "right from the beginning I said, 'She's got to have tits." But while they exist, they play hide-and-seek behind strategically placed beads so the film could retain its PG13 rating.