The chicken is a domesticated fowl, a subspecies of the red junglefowl. The chicken is one of the most common and widespread domestic animals, with a total population of more than 19 billion as of 2011. There are more chickens in the world than any other bird or domesticated fowl. Humans keep chickens primarily as a source of food, consuming both their meat and their eggs.
Chickens are omnivorous and eat a wide variety of food, but prefer seeds, insects, and other small animals.
The red junglefowl are the wild ancestors of the chicken that are still found in parts of Southeast Asia. The chicken was first domesticated in India more than 5,000 years ago.
The chicken was brought to Europe by the Romans, and it quickly became a popular food there. Chickens were introduced to the Americas by the Spanish in the 16th century.
Today, chickens are widely considered as a common poultry animal in many parts of the world. In 2010, there were more than 19 billion chickens in the world, making them the most common bird on the planet.
