A chicken coop is a building where female chicken

Chicken

The chicken is a domesticated fowl, a subspecies of the Red Junglefowl. As one of the most common and widespread domestic animals, and with a population of more than 24 billion in 2003, there are more chickens in the world than any other species of bird...

s are kept. Inside there are often nest box

Nest box

A nest box, also spelled nestbox is a man-made box provided for animals to nest in. Nest boxes are most frequently utilized for wild and domesticated birds, in which case they are also called birdhouses, but some mammalian species may also use them. Birdhouses are the most common types of nest...

es for egg laying and perch

Perch

Perch is a common name for fish of the genus Perca, freshwater gamefish belonging to the family Percidae. The perch, of which there are three species in different geographical areas, lend their name to a large order of vertebrates: the Perciformes, from the Greek perke meaning spotted, and the...

es on which the birds can sleep, although coops for meat birds seldom have either of these features.

A coop may have an outdoor run. Both the inside and outdoor floors of a chicken coop are often strewn with a loose material such as straw

Straw

Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such as barley, oats, rice, rye and wheat. It has many uses, including fuel, livestock bedding and fodder, thatching and...

 or wood chips to deal with chicken droppings and to allow for easier cleanup. Most chicken coops have some means of ventilation to help air out any smells.

Housing controversies

There is a long standing controversy over the basic need for a chicken coop. One line of thinking, called the "fresh air school" (which is held by most commercial poultry operations) is that chickens are mostly hardy but can be brought low by confinement, poor air quality and darkness, hence the need for a highly ventilated or open-sided coop with conditions more like the outdoors, even in winter. However, others who keep chickens believe they are prone to illness in outdoor weather and need a controlled-environment coop. This has led to two housing designs for chickens: Fresh-air houses with wide openings and nothing more than wire mesh between chickens and the weather (even in Northern winters), or closed houses with doors, windows and hatches which can shut off most ventilation.

Backyard coops

Backyard coops are small and built within a fence

Fence

A fence is a freestanding structure designed to restrict or prevent movement across a boundary. It is generally distinguished from a wall by the lightness of its construction: a wall is usually restricted to such barriers made from solid brick or concrete, blocking vision as well as passage .Fences...

d area (sometimes bounded by chicken wire

Chicken wire

Chicken wire, or poultry netting, is a mesh of wire commonly used to fence poultry livestock. It is made of thin, flexible galvanized wire, with hexagonal gaps...

) to let the chickens roam, peck and hunt for insects. If this kind of "yarding" is floorless and can easily be moved (or dragged) from spot to spot it is called a chicken tractor

Chicken tractor

A chicken tractor is a movable chicken coop lacking a floor. Chicken tractors may also house other kinds of poultry.Most chicken tractors are a lightly built A-frame which one person can drag about the yard...

. Many people, moreover in rural areas, keep a small flock of chickens from which they glean eggs and meat mostly for themselves. The number of small chicken coops in urban areas has been growing, which has led to manufactured chicken coops like the Eglu

Eglu

The Eglu is brand of chicken coop designed and marketed by Omlet Ltd in the UK that is intended for small-scale, backyard chicken keeping. The original design was by four graduates from the Royal College of Art, and was first shown at the degree show at the College in 2003.It was launched in April...

 which are designed for more cramped spaces and a tidier look.

Urban settings may have laws which regulate any backyard farming of livestock. Oakland, California

Oakland, California

Oakland is a major West Coast port city on San Francisco Bay in the U.S. state of California. It is the eighth-largest city in the state with a 2010 population of 390,724...

, bans roosters, with a rule that hens be kept at least twenty feet away from dwellings, schools and churches.

Other uses

• In American English
  American English
  American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
  
   the slang
  Slang
  Slang is the use of informal words and expressions that are not considered standard in the speaker's language or dialect but are considered more acceptable when used socially. Slang is often to be found in areas of the lexicon that refer to things considered taboo...
  
   phrase flew the coop means someone who has fled before being sent to jail ("The police had a warrant for his arrest, so he flew the coop!").
• American truckers call weigh station
  Weigh station
  A weigh station is a checkpoint along a highway to inspect vehicular weights. Usually, trucks and commercial vehicles are subject to the inspection....
  
  s chicken coops.
• In the poem Ballad of John Silver by John Masefield
  John Masefield
  John Edward Masefield, OM, was an English poet and writer, and Poet Laureate of the United Kingdom from 1930 until his death in 1967...
  
  there is a reference to drowning merchants "lamenting the absent chicken coop". In the age of sail, vessels on long voyages would often keep live poultry for meat and eggs within wooden coops stacked on deck. If a ship should sink or capsize these coops would typically come loose and float freely, making for an impromptu emergency floatation device. This maritime usage is archaic and may now be lost.