Zoologist George McGavin continues his exploration of the primate world, considering how the secret to their success is the ability to live in close-knit family and social groups. This is demonstrated by the emperor tamarin males conned into childcare in Peru and the South African vervet monkeys that have a sophisticated alarm system to protect them from predators. But living together often has its problems, like the Barbary macaques in Gibraltar who have their babies stolen by others out to impress their boss, the matriarchal ring-tailed lemur societies where females battle one another with their children in tow, and the hamadryas baboons of Ethiopia where the males rule with an iron fist