The agency turned to Bob Bailey, a pioneering animal behaviorist who had already overseen a number of hilarious projects, such as the Acoustic Kitty (a cat with a listening device) and the World War II-era pigeon missile (an actual missile full of actual pigeons that guided it by pecking a map). At this point, it's probably good to remember that there was quite a lot of LSD floating around Langley at the time.
Bailey planned to train his birds to carry listening devices that they would deposit on window ledges and rooftops. He also designed a tiny camera that the raven would activate by pushing it against a window. Because the world is apparently a cartoon, Bailey's plan was a roaring success, and the CIA happily shelled out the cash to build spy-raven training facilities. The next steps: motorcycle-riding mice and martial arts-practicing turtles.
"If we can't train them, we can feed them to the ravens."
Sadly, the spy-raven program was terminated in the 1970s. However, Bailey strongly insinuates that the ravens were successfully used in the field a number of times. He even jokingly hints that there might be CIA-trained "rogue" raven agents out there today. And that goddamn well better be the plot of the next Bourne movie.