So much of our life is influenced by who is in our social networks: we rely on extended families, friends of friends of friends, co-workers and their connections to gain intelligence on everything from what books to read to how to vote to which jobs to pursue. But we are by no means alone in this reliance: social networks also affect the daily experiences and, indeed, survival of individuals in many animal species. That chimpanzees and other primates have complex social lives has been well known for decades. More recent studies have revealed that the actions of single birds, dolphins and other creatures make complete sense only in their social context. These findings could affect everything from conservation efforts to understanding our own social networks.