Most of the "Foragers" (excluding Darwin) are named after automobiles, in relation to the main cause of the social collapse being gas shortage: Dakota (Dodge Dakota), Ford (Ford Motor Company), Viper (Dodge Viper), Torino (Ford Gran Torino), Nova (Chevy Nova), Max (could be a reference to the Metropolitan Area Express), Yukon (GMC Yukon), Victoria (Ford Crown Victoria), and Neon (Dodge Neon). Likewise, the "Rovers" are named after canines: Jackal, Mongrel, Shepherd, Wolf, Dingo, Lobo, Black Dog, Hairball, and Pug.