The common chicken (Gallus domesticus) is a member of the Phasianidae family that also includes pheasants, partridges, quails, and turkeys. Its ancestor, the red jungle fowl (Gallus gallus) was domesticated in Southeast Asia and China before 7000 BC and was valued for its eggs and cockfighting prowess. This ancestor evolved in India around 2000 BC into the common chicken, which spread as a source of food to the Middle East and eventually to the rest of the world.

Covered by nature with feathers to keep it warm and protect it from predators, the chicken is an omnivore that eats grains, seeds, insects, and small vertebrates. Its digestive system has a unique organ, the gizzard, that grinds and mixes the ingested food particles. In its natural habitat a chicken has a lifespan of three to five years, occasionally as long as fifteen. It is a social animal that lives in flocks, maintains an established pecking order, and occasionally will gang up on other animals such as a young fox. The male “crows”; the female “clucks” and lays eggs that hatch in about 21 days.

More than fifty billion chickens are grown each year as a source of meat and eggs. In the United States alone, more than eight billion chickens are eaten each year, compared to 34 million cattle and 130 million hogs. The average American eats more than 98 pounds of chicken each year. Over 300 million chickens are raised each year for egg production, mostly in factory farms.

Eating chickens may expose one to various pathogens, notably E. coli, Clostridium perfringens, Campylobacter, and Salmonella. Killing these bacteria requires a temperature of 165 F whether baking, roasting, broiling, poaching, microwaving, or frying. Washing raw chicken before cooking it merely spreads the bacteria to the sink, the kitchen counter, utensils, and to foods nearby. Cooked or raw chicken should be kept in the refrigerator at 40 F or lower. When purchased, the chicken is best placed in a disposable bag to keep it from contaminating other foods. After touching raw chicken, one should wash one’s hands with warm and soapy water.

Growing chickens clearly requires less land, water, and feed than cattle. Ethical concerns have been raised about modern industrial farming in which chickens are raised in overcrowded areas with no access to the outdoors. There are also concerns about the overuse of antibiotics leading to antibiotic resistance and the development of pathogens causing many unnecessary human deaths. In the past carcinogenic arsenic containing drugs used to be added to the feed of chicken to make them grow faster and give their raw meat an attractive pink color. In America chickens are now “inspected for wholesomeness” by the US Department of Agriculture or a state agency to rule out contamination by chemical and certain pathogens. In recent times, activist shareholder movements have campaigned to induce industrial companies to adopt more humane and ethical practices. About ten million households keep chickens as pets.

In the Bible, Matthew and Luke record Jesus’ desire to gather the children of Jerusalem “as a hen gathers its brood under its wings,” but was denied this. Too, Christ predicted that the rooster would not crow three times before Peter would deny him, leading to his sacrifice. Some Orthodox Jews believe that sins accumulated throughout the past year are transferred to a chicken in the ritual of kapparot and that, upon its sacrifice, they will obtain atonement. To consume the bird, Muslims must kill it humanely and in accordance with halal standards.

In common parlance to “play chicken” is to test two or more parties’ courage, to be “chicken-livered” is to be timid and cowardly, and for generations grandmas have recommended chicken soup, perhaps less so for its chemotactic and anti-inflammatory activity than for the proven benefits of tender love and care.