The CIA used cats to spy on Soviet embassies and the Kremlin during the Cold War
In the 1960s (during Cold War), the Central Intelligence Agency of the U.S. federal Government devised a covert plan to keep tabs on the Russian diplomats in the Capitol. Interestingly, they used non-human techniques to spy on the Russians. In a project codenamed “Acoustic Kitty”, a microphone was surgically implanted into a female grayish white cat’s ear canal, a small ¾ inch radio transmitter at the base of its skull and a thin wire into its fur.
As a result, the cat would be able to record and transmit sound from its surroundings safely. But distraction like the cat’s sense of hunger was dealt in another operation. However their attempt for sound test was unsuccessful as the first trained cat was run over by a cab. The CIA researchers concluded that environmental and security factors in a real situation made the project impractical. The $20 million projected was cancelled in 1967.