The task is to go into a forest and capture the rabbit in there.
The FBI goes in, they place inside operatives into the animal kingdom, question all the tree witnesses, and interrogate even the rocks. After 3 months of effort, they come out, and conclude that the rabbit does not exist, and was just an urban myth.
The CIA goes in next. In a week, there is an uprising of freedom fighters who seek to overthrow the hierarchy, which escalates until the forest burns down. They present the corpse of a rabbit and say it resisted.
Not impressed, the KGB is sent in to the next forest. By the afternoon, they come out, dragging a bloody and bruised bear behind them, who instantly confesses: “I am rabbit. My mother and father were rabbits.”