FarmVille released the chicken coop in November 2009 as a functional item that stores--you guessed it--chickens. When you harvest your chicken coop, you earn six coins times the number of chickens in the coop, and each coop can hold 20 chickens. You can purchase a chicken coop from the market for 5,000 coins, but you aren't able to purchase more than one. If you want more than one chicken coop, there is a way to get another--but it won't last long!
Instructions:
1) Log onto Facebook and open FarmVille.
2) Navigate to your "Gift Inbox."
3) Click the button reading "Make a Wish."
4) Click the button that reads "Send a Wish." Choose a friend and designate a chicken coop as the gift you'd like to receive. The request will appear on your friend's wall.
5) Wait for your friend to fulfill your request. You'll receive a second chicken coop, but FarmVille will immediately turn the coop into a chicken.
Source: eHow