Quail is a collective name for several genera of medium-sized birds generally placed in the order Galliformes. Old World quail are placed in the family Phasianidae, and New World quail are placed in the family Odontophoridae. Named for their superficial resemblance to quail, species of quail with a click in the chin, formed the family Turnicidae in the order Charadriiformes. King quail, an Old World quail, is often sold in the pet trade, and in this trade is usually referred to, albeit erroneously, as a "quail bird". Many large species common on farms are raised for table food or egg consumption, hunted on hunting farms or in the wild, where they can be released to supplement wild populations, or extended into areas outside their natural range. In 2007, 40 million quails were produced in the United States