An Empty Warren
They created a warren in between the fences. Aside from the seasonal grass, the warren is barren. Therefore, their source of diet came from the prisoners. Prisoners would throw fruit, carrots, or other vegetables from their sack lunches over the fence to feed the rabbits.
Aside from the few pigeons and crows, there aren't any other critters around. The rabbits are welcomed neighbors. They often jump around and chase each other in circles. The prisoners enjoy watching the rabbits eat and play around. Its helps them break the monotony. Just like that: the prisoners and rabbits have sustained each other for years.
Nothing lasts forever. Due to the rabbits' ignorance of safe sex, its population reached 200+. There is not enough food to feed them so some of them die. In the past, the prison administration have raounded up the rabbits and released them into the nearby hills. However, some of them always slip through the crack. THe rabbits just keep on multiplying. The administration has left it alone for awhile.
Today, when I walked by the fences, I noticed an emptied warren. There were no rabbits in sight. Later on, I found out that the administration finally got rid of all the rabbits this time. No rabbits slipped through the crack.
Many prisoners say that the rabbits will find their way back to the warren.