Chicken

Chickens (sometimes referred to as "Ducks" ) are passive mobs found in Minecraft. They have white feathers and wings, with a yellow beak and a red wattle. Chickens supply feathers, raw chicken and chicken eggs, essential for arrows, food and cakes, respectively. Chickens are 0.875 blocks tall, 0.5 blocks wide and 0.8125 blocks long. Chickens spawn in broad daylight, and can spawn in groups of 2-6. A thrown egg has a 1 in 8 chance of hatching a chick, and a 1 in 256 chance of hatching 4 chicks at once.

Behavior
Chickens appear to wander around aimlessly, but actually have decent path-finding ability. They will make no attempt to stay out of water. Chickens are drawn to light in a dark environment, and will follow the player if the player is holding wheat (see Breeding). They will flee when attacked.

When a chicken falls from a height, it quickly flaps its wings and falls slowly to the ground to prevent fall damage. Chickens will not climb up a ladder, but may be pushed up by the player.

While active a chicken will lay an egg every 5-10 minutes (6000 to 12000 ticks). In one experiment, it took 40 minutes for 9 chickens to lay 50 eggs (on average, 7.2 minutes/egg per chicken).

Breeding
Chickens can be hatched by throwing chicken eggs, allowing them to be easily bred. Each egg has a 1/8th chance of hatching a chick and a 1/256th chance of hatching 4 chicks. This means that 5 stacks of eggs (80 total) will produce an average of 11 chicks.

Chicks move faster than adults and make different sounds. They take an average of 20 minutes to grow into adults. They do not lay eggs and will not drop resources if killed.

Adult chickens lay an egg every 7.5 minutes, so it takes an average of 55 minutes to produce a chick by collecting and throwing the eggs of a single chicken. Doing this continuously with a large number of chickens (several dozen) will double the population roughly every hour.

Chickens can also be bred by feeding them wheat. The parent chickens will have a delay of five minutes until they can breed again. Newborn chicks will follow their parents (or a nearby adult if hatched from an egg).

It is possible to herd chickens along with any other animal if you simply walk by a chicken while holding wheat. The chicken will follow you wherever you go. You can do this to lead animals into fenced areas for easy breeding. This will still work when you're in a boat, if you're careful not to outrun them -- this is an alternate means to lead a seed group long distances.

Farming
The player can farm chickens quite easily by making a safe, enclosed area. Making a chicken colony is a great way to get an unlimited supply of feathers, raw chicken and chicken eggs. Fully automatic egg farms are also possible, since live chickens drop eggs periodically. The usual method is to place the chickens in a pool of water held up by signs so that their eggs will fall through the water into a collection area.

History
Chickens were first introduced in Alpha Version 1.0.14 (Seecret Friday 7).

Raw chicken was introduced in Beta 1.8 with the introduction of the Hunger system. Before this, chickens dropped only feathers on death.

Since Snapshot 12w07a, chickens have the new AI system. 

Trivia

 * When a chicken is killed and has a boost from the hit or is thrown over a cliff by the hit, the "corpse" will also fall more slowly than normal, and the wings will still make a flapping animation.
 * When a chicken is riding a minecart, it is impossible to attack the chicken rather than the cart as it is completely within the hitbox of the cart.
 * Chickens are the only Overworld mob (without the use of hacks/inventory editors) that can be spawned in the Nether in Survival mode, by hatching them from throwing chicken eggs.
 * Chickens are sometimes mistaken for ducks due to their wide beaks and ability to swim.
 * Probably inspired by this, Notch tweeted that he changed the chickens to ducks a few weeks before the end of Beta, causing a turmoil on Twitter. A few days later, Jeb, still getting feedback on the idea, stated that it was just a joke.
 * If you throw chicken eggs at glass panes, there is a small chance that the Chicken will spawn on the other side of the panes.
 * Despite being an animal that does not give live birth, chickens in-game are able to give live birth.
 * Chicks can be lured by wheat.
 * There is no texture for the underside of a chicken's head, allowing you to see through it and see the inside.
 * Ocelots will attack chickens.
 * Studies show that chickens are the quickest at getting out of traps or structures when there is an opening.