Incredible Secret Spy Devices of History

From very dangerous weaponized umbrellas, to exploding bats, let’s see the most incredible devices and gadgets spies have used.

August 1, 2022・

11 min read

When you watch a spy movie, you may roll your eyes when another random gadget turns out to be a powerful laser. But not all of them are ridiculous clichés. Truth is, reality really is stranger than fiction.

From very dangerous weaponized umbrellas to exploding bats, let's explore some of the most incredible, and unbelievable tools and methods used by spies in order to complete their missions.

10. Animal Instincts

When most of us think of spies, we picture sharply-dressed, pistol-holding smooth-talkers. We probably wouldn't picture pigeons but perhaps we should. As far back as the decadent times of Ancient Rome, pigeons have been used to pass secret messages between important people.

These common birds with an incredible innate homing ability directing them to places over a thousand miles away have continued to be some of our best undercover agents ever since. During the First World War, pigeons were strapped with small, rudimentary cameras and sent into enemy airspace.

After a controlled time-delay, the camera would snap pictures of enemy bases from above, providing an invaluable military advantage. British intelligence services at the time even considered strapping explosives or biological weapons onto them so they could be detonated on target locations.

But pigeons aren’t the only species that people have used to spy on each other. There have been countless instances of humans using animals’ innate abilities and senses to our advantage. The next agent of animal subterfuge is the common housecat.

Known officially as ‘Acoustic Kitty’, a CIA operation during the Cold War involved implanting a radio transmitter, a microphone and an antenna inside the body of a cat. The cat – still alive – was sent into the vicinity of two Soviet suspects, with the intention that it would record their conversation. Sadly, the cat was allegedly hit and killed by a car soon after being released.

Naturally, the ethics of the case have been a matter of concern in recent years. However, the difficulty of making a cat obedient enough to carry out the work has cemented this case as one of the most bizarre failures in the history of animal spies.

9. Secret Tools for Survival

Being captured as a spy can leave you in dangerous circumstances. Consequently, some ingenious devices and methods have been used in the past to help spies survive tough situations. However, the solutions weren’t always pleasant. Case in point: the CIA’s Cold War concealed survival kit.

This kit was designed to be thoroughly hidden in case of searches. Would you be able to guess where? A worryingly-large pellet was kept inside the user. They will keep it there until they were able to pass it safely, at which point they would – presumably – clean it off a little, before cracking it open and retrieving the tools and weapons inside.

8. Fun and Games

Being a prisoner of war in Nazi Germany was about as far from a fun experience as possible. But, as part of the strange logic of the Nazi leadership, prisoners of war were allowed to receive games and pastimes from humanitarian groups like the Red Cross. Seizing upon this opportunity, allied forces began shipping modified versions of Monopoly to POWs.

Shallow indentations were cut into the board to hide tools and maps. Some of the playing pieces could also be re-purposed as tools. Sometimes, there was even real money hidden in among the Monopoly money.

7. All Mapped Out

Monopoly boards weren’t the only places where vital escape tools were hidden for spies in the twentieth century. Prisoners of War often received innocuous-looking decks of cards that – when wet – could be peeled apart to reveal a map of the local area.

This would have been incredibly useful for any escape attempts, as many prisoners found themselves in totally unfamiliar territory. For those looking to keep as low of a profile as possible, a unique spin on a classic idea became available during World War 2: silk maps.

These aren’t meant to be worn as a nice soft scarf, even though they’d probably serve that purpose fine too. These maps were crafted out of soft fabric for several reasons: they wouldn’t deteriorate in the rain like their paper counterparts, nor would they tear easily. Most importantly, they did not rustle – an easily neglected but hugely important factor in remaining undetected.

6. Spy-tech

Spy technology has come an incredibly long way in the past 100 years, evolving from very basic, low-quality microphones and cameras, into the drones, phones and the always-listening Google homes we see today.

Modern technology can achieve incredible feats, like the cleverly-inconspicuous cellular interception rucksack, which looks like a normal backpack but has the incredible technological ability to intercept up to 30 phone calls at the same time.

But even as early as the mid-twentieth century, we were achieving some phenomenal progress in the world of espionage. The microdot camera was a brilliant example of secretive genius.

The tiny camera, perfected in the 1960s, could photograph sensitive documents and reduce the image to the size of a pinprick. These could later be viewed using a microscope. This meant that confidential images could be easily snuck away, due to their miniscule size.

5. Hideaway

Sometimes, as a spy, you pull the short straw and end up on hideout duty. This isn’t usually the cop-drama, sitting in a car with coffee and donuts, waiting for the perp to arrive, type of situation. A CIA espionage guidebook, ‘The Official CIA Manual of Trickery and Deception’ advises on a clever but rather claustrophobic method of concealing a spy in a vehicle, for surveillance of the vehicle’s owner.

This involves modifying the fuel tank so that one half is empty, allowing the unlucky spy to reserve themselves a very cozy spot in the vehicle that’s accessed through a hidden compartment in the boot.

However, spying often involves concealment of a different kind. Throughout history, intelligence gatherers have fallen over each other trying to ensure the safe transport of secret messages and items.

Even as far back as the regal courts of Queen Elizabeth I in England, her trusted spymaster was able to intercept coded messages transported in beer barrels. Due to his findings, and decoding abilities, Sir Francis Walsingham was able to thwart a major assassination plot against his Queen.

4. Making Invisible Visible

Secret messages don’t always reach their target. Interception is something that most secretive organizations prepare for – and they do it in some pretty clever ways. Invisible ink is one such practice, and you may be surprised to find that this is not a particularly recent invention.

Records indicate that invisible ink was being used as far back as the fourth century BC, and one of its famous more recent proponents was none other than George Washington. Washington used a special type of ink that could only be made visible with the use of a secret and specific second chemical. The name of the chemical is still classified to this day.

As demonstrated by the craftiness of Francis Walsingham, spies have always been gifted interceptors too. While developments in spying have led us to some pretty uncomfortable places (like the nosy NSA), they have also given us some very unique inventions.

An interesting example is the ‘envelope x-ray spray’, which allows one to peek inside at the contents of an envelope for a moment before the transparency fades away moments later.

3. Code to Victory

Of course, one of the smartest ways to keep your message from being read by someone who isn’t supposed to read it, is to translate it into a secret code. This technique has been dated as far back as Ancient Greece and beyond, with the use of scytales.

In this era, ribbons inscribed with seemingly-random alphabetical characters were passed between military leaders. When the ribbons were wrapped around a block of a specific size and shape - of which both the sender and recipient would have safely locked away - the letters would align to spell out important messages regarding military plans and information.

Things have become infinitely more complex as time has passed, particularly with the development of computers, which can generate encryptions that are near-impossible to crack.

Similarly, advancements in manufacturing have allowed for the production of sneaky objects like this compact mirror, another brainchild of the CIA. Useful for powdering your nose, the hidden secret of this little looking-glass is revealed when tilted at just the right angle – if done correctly, a secret code is revealed.

2. Killer Accessories!

It’s no secret that the life of a spy can involve regular brushes with death. Sometimes, in following orders, a spy must carefully and untraceably take out a target, as popularized by 007's License to kill. Ingenious inventions such as the CIA Stinger, a 22-caliber single-bullet firing device concealed within a toothpaste tube, were designed to be able to remain undetected as part of an agent’s travel bag.

I just hope no one ever tried to squeeze this one onto their toothbrush – that’s a dentist bill no one wants to pay. Similar inventions were common in the mid-twentieth century, like the Sedgley Fist Gun, with probably the coolest weapon name ever.

The glove would fire a single round when the wearer curled their hand into a fist, delivering an unexpected and lethal blow to the unfortunate target when punched.

But perhaps the most bizarre of all is the Bulgarian Umbrella. A pellet of ricin, a lethal and almost untraceable poison, would sit in the tip of the umbrella, waiting to be injected into a victim with the flick of a switch on the umbrella’s handle.

In fact, even the US Department of Defense has experimented with hidden weapons inside umbrellas. Charles Senseney, a former weapons developer for the DOD testified to the Senate intelligence committee that he designed one for them that could fire darts. He spoke out in regards to the killing of JFK, who many believe was killed by this type of device.

This hypothesis is nurtured by the presence of a strange man holding an umbrella near JFK when he was assassinated, despite the fact it wasn’t raining. Though unconfirmed, there’s definitely a trend for putting weapons in items as mundane as possible; as these are the last things that a target would perceive as threatening or suspicious, which is what makes them so effective.

1. Boom for improvement

One of the central principles of being a good spy is going unnoticed. Sometimes, though, history has shown that secret organizations can lack a certain subtlety, at times. Spy plots can go explosively wrong. Granted, the use of explosives in secret operations has had some success, like nineteenth-century coal torpedoes, utilized during the American Civil War.

These were designed to be mistaken for real coal and were thrown into the furnaces of Union steam transportation vehicles, which would explode, killing crewmen and passengers, and leaving the engines out of action.

For the most part, however, spies and explosives don’t tend to mix too well. Through the CIA’s many attempts to assassinate Fidel Castro, poisoned and explosive cigars were used but were repeatedly met with failure. Castro was clearly up to date on his cartoons.

Not even sweet, delicious chocolate was safe from the busy fingers of spies in the Second World War. In a bizarre turn of events, elaborate designs for an explosive chocolate bar – made with real, edible chocolate – were found by British intelligence. This was discovered to be part of a wider plot to assassinate prime minister Winston Churchill.

Luckily for Churchill, the plan never came to fruition, but the result would have been more than a toothache. Once the bar had been broken, with the classic, satisfying pop, a short fuse would activate. That would trigger the chocolate bar’s lethal payload, which would detonate doing serious damage to anyone in the surrounding area.

Unfortunately, our animal friends haven’t been too lucky in the field of explosive espionage, either. In perhaps the most baffling of all espionage tactics which was, unsurprisingly, another one of the CIA’s whacky schemes, a programme exploring the use of explosive bats was carried out during World War Two.

Explosive rats had previously been attempted in World War One but to little effect. The attempts to weaponize bats in the Second World War met with similar degrees of failure.

According to the plans, a large canister would be dropped from a plane over Japanese cities, at which point a parachute would be deployed. A canister would then open, releasing hundreds of bats to settle in the Japanese buildings below.

Each bat was equipped with a small incendiary bomb on a timer, and if all went according to plan, the bombs would set fire to the houses, causing widespread destruction. While the plan seemed promising at first, disaster struck in the testing phases, when the bats incinerated an air base after an error in their deployment.

The costly damage contributed to the eventual cancellation of the scheme. They might not always have gone to plan, but it's hard to deny the level of creativity that went into some of these inventions. As we get better and better at spying on each other, and carrying out covert operations, I wonder what crazy inventions intelligence agencies will come up with next.

If you enjoyed reading about these incredible secret spy devices, you might want to read this article about the sneakiest spy devices ever created. Thanks for reading.