Book excerpt: The groundbreaking, New York Times–bestselling book on canine behavior and how dogs become family from the author of The Hidden Life of Dogs. In the sequel to her New York Times bestseller The Hidden Lives of Dogs, anthropologist Elizabeth Marshall Thomas profiles the assortment of canines in her own household to examine how dogs have comfortably adapted to life with their human owners—and with each other. Thomas answers questions we all have about our dogs’ behavior: Do different barks mean different things? What makes a dog difficult to house-train? Why do certain dogs and cats get along so well? How does one of her dogs recognize people he sees only once a year, while another barks at strangers she sees every day? What leads to the formation of packs or groups? As Publishers Weekly raves, “no one writes with greater emotional intelligence about man’s (and woman’s) best friend than Thomas.”