typically referred to as common fowl or domestic fowl. In Australian vernacular English the word chook provides the generic term for the species (e.g. "a cooked chook" or "she keeps chooks"); which enables chicken to commonly retain its original sense of a young or recently hatched bird. Chick is then rarely used to mean chicken, but is mainly used in Merriam-Webster's "Sense 1b" viz. the young of any bird. Etymology According to Merriam-Webster, the term rooster (i.e. a roosting bird) originated in the mid- or late 18th century as a euphemism to avoid the sexual connotation of the original English cock, and is widely used throughout North America. Roosting is the action of perching aloft to sleep at night. Biology and habitat Chickens are omnivores. In the wild, they often scratch at the soil to search for seeds, insects, and even animals as large as lizards, small snakes, or sometimes young mice. The average chicken may live for 5–10 years, depending on the breed. The world's oldest known chicken lived 16 years according to Guinness World Records. Roosters can usually be differentiated from hens by their striking plumage of long flowing tails and shiny, pointed feathers on their necks (hackles) and backs (saddle), which are typically of brighter, bolder colours than those of females of the same breed. However, in some breeds, such as the Sebright chicken, the rooster has only slightly pointed neck feathers, the same colour as the hen's. The identification can be made by looking at the comb, or eventually from the development of spurs on the male's legs (in a few breeds and in certain hybrids, the male and female chicks may be differentiated by colour). Adult chickens have a fleshy crest on their heads called a comb, or cockscomb, and hanging flaps of skin either side under their beaks called wattles. Collectively, these and other fleshy protuberances on the head and throat are called caruncles. Both the adult male and female have wattles and combs, but in most breeds these are more prominent in males. A 'muff' or 'beard' is a mutation found in several chicken breeds which causes extra feathering under the chicken's face, giving the appearance of a beard. Domestic chickens are not capable of long-distance flight, although lighter chickens are generally capable of flying for short distances, such as over fences or into trees (where they would naturally roost). Chickens may occasionally