Chickens (Gallus domesticus) are domestic birds that cannot fly. There are over 150 different breeds of chicken that come in various colours, patterns and sizes. The chicken is believed to have descended from the wild Indian and south-east Asian Red Junglefowl which is biologically classified as the same species.

With a population of more than 24 billion in 2003, there are more chickens in the world than any other bird. Chickens provide two sources of food frequently consumed by humans: their meat, also known as chicken, and eggs which they lay.

Chickens have a great usefulness to humans. Chickens can be kept as pets, for breeding, egg laying and a food product. There are many different breeds that come in a variety of colours.

A female chicken is called a 'hen'.   A male chicken is called a 'rooster'     Young chickens are called 'chicks' or 'poults'.   A group of chickens is called a 'flock'.