10 Strange Weapons Invented During World War II

"Bat bombs" were just one of the unusual weapons developed during the Second World War.
"Bat bombs" were just one of the unusual weapons developed during the Second World War.
WallpaperFlare // Public Domain

Necessity is the mother of invention, so the saying goes, and World War II was certainly a time of need. For good, for bad; to kill, to cure; to build and to destroy. Weapons were invented that changed the course of the war, such as the B-17 Flying Fortress, the Soviet T-34 tank, the Spitfire, and Hurricane, and, of course, the atomic bomb. Inventions like synthetic rubber, the Jeep, and duct tape also helped the Allies win World War II.

But not all the weapons invented during World War II were quite as effective—some were downright strange. Bat bombs, exploding rats, wind cannons, and fecal sprays were just some of the bizarre weapons invented during the conflict. While some were used in combat, others never progressed beyond the initial testing phase.

1. The Panjandrum

In 1943, the British Directorate of Miscellaneous Weapons Development (DMWD) was asked to develop a weapon that could penetrate the concrete defenses of the Atlantic Wall, an extensive system of Nazi-built coastal fortifications. And so the DMWD invented the Panjandrum. The huge contraption consisted of two wheels connected by a sturdy, drum-like axle, with rockets on the wheels to propel it forward. Packed with explosives, it was supposed to charge toward the enemy defenses, smashing into them and exploding, creating a breach large enough for a tank to pass through. But when it was tested on an otherwise peaceful English beach, things didn’t go quite as planned. The 70 slow-burning cordite rockets attached to the two 10-foot steel wheels sparked into action, and for about 20 seconds it was quite impressive. Until the rockets started to dislodge and fly off in all directions, sending a dog chasing after one of them and generals running for cover. The rest was sheer chaos, as the Panjandrum charged around the beach, completely out of control. Unsurprisingly, the Panjandrum never saw battle.

2. The Goliath Tracked Mine

In 1940, the Wehrmacht recovered a strange, remote-controlled prototype vehicle from the River Seine. Designed by the French vehicle designer Adolphe Kégresse, this prototype inspired the Germans to develop their own remote-controlled vehicle, primarily as an anti-tank weapon. The result was the Goliath Tracked Mine, a 1-foot-tall, 4-foot-long tracked vehicle that could carry around 132 pounds (60 kilograms) of high explosives. Steered remotely, it could be driven beneath enemy tanks and detonated. The Goliath, however, had a number of issues. The remote control connection was achieved via a 2132-foot-long cable between the vehicle and the driver. Enemy soldiers quickly learned they could neutralize the Goliath by cutting the cable. It was also painfully slow at just 6 miles per hour, had a woeful ground clearance (meaning it could easily become stuck), and was only covered with thin armor. Nevertheless, the Germans produced 7564 Goliaths and used the weapons in battle during the Warsaw Uprising and on the beaches of Normandy. The vehicle wasn’t deemed much of a success at the time, but it did pave the way for the development of later remote-controlled weapons. Captured Goliaths also provided some fun for U.S. soldiers.

3. Fu-Go Balloon Bombs

In 1944, Japan came up with a nefarious but quite ingenious plan to drop bombs on the U.S. Using the jet stream over the Pacific Ocean, they launched paper balloons carrying explosive devices, which would float silently across the ocean to their enemies, instilling fear and panic in America. That was the plan, anyway. They launched the first balloon on November 3, 1944, and it’s estimated that between then and April 1945 about 1000 “Fu-Go” balloon bombs reached North America. After the war, records uncovered in Japan revealed that some 9000 launched in total. Despite so many launches, only one resulted in the loss of human life. On May 5, 1945, a pregnant woman and five children were killed in the woods near Bly, Oregon, when they began playing with the large paper balloon, which exploded. Due to the uncontrolled nature of the balloon bombs and the uncertainty of atmospheric conditions, the experimental weapon was largely unsuccessful and to this day remains relatively unknown. It is, however, widely considered to be the first intercontinental weapon system.

4. Bat Bombs

The fiery aftermath of a batty experiment gone terribly wrong.United States Army Air Forces, Wikimedia Commons // Public Domain

Shortly after the attack on Pearl Harbor, a Pennsylvania dentist named Lytle S. Adams contacted the White House with a plan of retaliation: bat bombs. The plan involved dropping a bomb containing more than 1000 compartments, each containing a hibernating bat attached to a timed incendiary device. A bomber would then drop the principal bomb over Japan at dawn and the bats would be released mid-flight, dispersing into the roofs and attics of buildings over a 20- to 40-mile radius. The timed incendiary devices would then ignite, setting fire to Japanese cities. Despite the somewhat outlandish proposal, the National Research Defense Committee took the idea seriously. Thousands of Mexican free-tailed bats were captured (they were, for some reason, considered the best option) and tiny napalm incendiary devices were built for them to carry. A complicated release system was developed and tests were carried out. The tests, however, revealed an array of technical problems, especially when some bats escaped prematurely and blew up a hangar and a general's car. In December 1943, the Marine Corps took over the project, running 30 demonstrations at a total cost of $2 million. Eventually, however, the program was canceled, probably because the U.S. had shifted its focus onto the development of the atomic bomb.

5. Exploding Rats

Britain’s Special Operations Executive (SOE) invented a whole range of strange and often disguised devices for hiding, killing, and blowing things up during World War II. But the SOE really reached new levels with the exploding rat. The idea was simple: Around 100 dead rats were sliced open, stuffed with plastic explosives, and stitched back up. If all went according to plan, the rats would be placed near strategically identified boilers. Upon discovering a dead rat, someone would chuck it into the boiler, which would create a massive explosion. However, the plan was never put to the test, as the Germans intercepted the container of dead rats. Despite this failure, the rats had an unforeseen benefit: The Germans were now worried about the presence of exploding rats, and began to hunt high and wide for the spec-op rodents. In a report, the SOE noted that “The trouble caused to [the Germans] was a much greater success to us than if the rats had actually been used.”

6. Pigeon-Guided Rockets

Mammals weren’t the only ones roped into World War II military plans. The ability to successfully aim missiles was a major concern during World War II, and much brainpower was devoted to the task. One possible solution came from B.F. Skinner, a respected psychologist and inventor who believed in the power of pigeons. He had previously trained the birds to pull levers as part of his psychological research. So why not train them to guide bombs? Despite some doubts from the National Research Defense Committee, they nonetheless decided to give Skinner $25,000 for the development of his idea, code-named “Project Pigeon.” Skinner built a nose cone that housed three kamikaze pigeon cockpits. Each pigeon sat in front of a tiny electronic screen that projected an image of the ground below. The pigeons were then trained to recognize a target, and upon seeing it, would peck the screen. When all three pecked together, cables attached to their heads would adjust the missile’s flight path and guide it to the target. As bizarre as this all sounds, a successful demonstration was carried out. In 1944, however, the still-skeptical research committee terminated the project, without any of the pigeons seeing combat.

7. The Windkanone

Of the numerous Nazi Wunderwaffen (wonder weapons) developed during World War II, the Windkanone, or Wind Cannon, was one of the least successful. Rather than launching flak or other projectiles at enemy aircraft, this strange cannon was designed to disrupt low-flying enemies with a blast of air. The Windkanone was a 35-foot cast-iron tube with a 3-foot diameter. When fired electrically, an ammonia hydrogen mixture exploded in the chamber, forcing a rush of air through the cannon. This wind was capable, in theory, of disrupting aircraft within a range of 492 feet (150 meters). In 1945, a wind cannon was mounted on a bridge over the River Elbe, but it proved rather useless. The disruption to enemy aircraft turned out to be so minor that the weapon was eventually abandoned.

8. The Krummlauf

The ability to shoot around corners without breaking cover offers obvious advantages. With this in mind, the Germans developed the Krummlauf, a bent barrel attachment for the Sturmgewehr 44 assault rifle. They made two types, one for infantry use and one for firing from inside armored vehicles. The infantry model had a 14-inch barrel, with a 4-inch straight barrel, a 5.5-inch curved section and another 4.5 inches of straight barrel at the end. It was held like a normal assault rifle and aimed using a periscope sighting device. Due to the curvature, bullets typically broke in half when fired, making the Krummlauf practical only at short ranges. And because of the stresses placed on the barrel when firing, the Krummlauf had a short lifespan. It became unusable after firing 150 to 300 rounds. For these reasons, the Krummlauf wasn’t commonly seen on the battlefield. Still, the idea made sense, and designers are still playing with the concept today.

9. The Bob Semple Tank

The Bob Semple Tank is often regarded as one of the worst tanks ever built, but has a certain merit for at least trying something—anything—in a bad situation. During World War II, New Zealand became increasingly worried about the potential of a full-scale Japanese invasion, in which New Zealand would be pretty much on its own and cut off from Allied assistance. And without the means to produce armored fighting vehicles, it would be horrifically outgunned by the Japanese war machine. Enter Bob Semple, New Zealand’s Minister of Works, who came up with a plan: The creation of a domestically made tank using the chassis of a conventional 6-ton bulldozer. Semple oversaw the assembly of a fleet of 81 D8 Caterpillar tractors, which were then encased in a few sheets of corrugated iron, offering very little protection to the eight-person crew inside. Six 7.62-milimeter Bren guns were then attached to the front, rear, and sides of the vehicle, resulting in an ungainly mobile pillbox that moved at just 14 miles per hour. Thankfully, the Bob Semple Tank never saw combat. It’s now remembered with some affection, however, as the spirit in which it was created has gone some way to offset its reputation as quite possibly the worst tank ever made.

10. Who, Me?

In 1943, Private Ernest Crocker, a chemist who had worked on developing poisonous gases for the military, was recruited for a foul-smelling task: the creation of a military-grade stink bomb. The plan was to supply this stink bomb to the French Resistance, who would use it to spray German officers to embarrass them and, in turn, reduce overall troop morale. After months of testing the world’s most putrid scents, Crocker finally settled upon a formula that presented a concoction of smells including vomit, rancid butter, urine, rotten eggs, foot odor, and excrement, all in one delightful spray called Who, Me?. The unfortunate technicians at Maryland Research Laboratories who designed the packaging for the spray often wound up covered in the stench. Once the packaging problems had been solved, 600 units of Who, Me? were prepped for deployment, but the war ended before the spray saw any action. Crocker spent the rest of his career studying smells and flavors, helping to establish sensory science and food technology as scientific fields.

Looking to Downsize? You Can Buy a 5-Room DIY Cabin on Amazon for Less Than $33,000

Five rooms of one's own.
Five rooms of one's own.
Allwood/Amazon

If you’ve already mastered DIY houses for birds and dogs, maybe it’s time you built one for yourself.

As Simplemost reports, there are a number of house kits that you can order on Amazon, and the Allwood Avalon Cabin Kit is one of the quaintest—and, at $32,990, most affordable—options. The 540-square-foot structure has enough space for a kitchen, a bathroom, a bedroom, and a sitting room—and there’s an additional 218-square-foot loft with the potential to be the coziest reading nook of all time.

You can opt for three larger rooms if you're willing to skip the kitchen and bathroom.Allwood/Amazon

The construction process might not be a great idea for someone who’s never picked up a hammer, but you don’t need an architectural degree to tackle it. Step-by-step instructions and all materials are included, so it’s a little like a high-level IKEA project. According to the Amazon listing, it takes two adults about a week to complete. Since the Nordic wood walls are reinforced with steel rods, the house can withstand winds up to 120 mph, and you can pay an extra $1000 to upgrade from double-glass windows and doors to triple-glass for added fortification.

Sadly, the cool ceiling lamp is not included.Allwood/Amazon

Though everything you need for the shell of the house comes in the kit, you will need to purchase whatever goes inside it: toilet, shower, sink, stove, insulation, and all other furnishings. You can also customize the blueprint to fit your own plans for the space; maybe, for example, you’re going to use the house as a small event venue, and you’d rather have two or three large, airy rooms and no kitchen or bedroom.

Intrigued? Find out more here.

[h/t Simplemost]

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

12 Facts About the End of World War II

American servicemen and women in Paris celebrate on V-J Day, marking the end of World War II.
American servicemen and women in Paris celebrate on V-J Day, marking the end of World War II.
Office of the Chief Signal Officer, National Archives, Wikimedia Commons // Public Domain

On August 14, 1945, President Harry S. Truman announced the Japanese government had surrendered, a decision that would bring World War II to a close. Emperor Hirohito of Japan informed his own citizens on August 15, yet there was still work to be done. The written agreement that formalized the surrender wasn’t signed until September 2 of that year at a gathering aboard the USS Missouri in Tokyo Bay.

Communities around the globe have celebrated August 14, August 15, or September 2 as Victory Over Japan Day, or V-J Day for short. Here are a dozen facts about the surrender 75 years ago this summer and the events that led up to it.

1. The Battle of Okinawa marked the last major battle in World War II.

Over 60,000 American soldiers and marines arrived at the shores of Okinawa on April 1, 1945. The island south of Kyushu formed a logical gateway for an invasion of Japan, and U.S. troops were prepared for a fight. Eighty-one days of incredibly savage combat by air, sea, and land followed, hampered by dense forest and volcanic crags. The Allies emerged victorious, but 12,000 Americans were killed in the effort. Japan’s forces lost around 90,000 troops, and 100,000 civilians also died in the battle.

2. Before V-J Day, V-E Day—Victory in Europe Day—fell on Truman’s 61st birthday.

Sworn into office on April 12, 1945, following the death of President Franklin D. Roosevelt, Truman got to share an exciting piece of news early in his term. The Allies formally accepted Germany’s unconditional surrender on May 8—President Truman’s birthday. “Our victory is but half won,” Truman said. Though the violence in Europe had ended, things were coming to a head in the Pacific theatre.

3. To end World War II, the U.S. made a strategic decision to bomb Hiroshima and Nagasaki instead of other Japanese cities.

An atomic bomb had been successfully tested in the New Mexico desert on July 16, 1945. By deploying nuclear weapons against Japan, Truman and his advisors hoped to force an unconditional surrender—and avoid the need for a full-scale U.S. invasion of the Japanese mainland.

For maximum impact, it was decided the ideal targets would be cities that had suffered little damage from earlier bombings. Because of its cultural significance as Japan’s former capital, Kyoto was taken off the list. The target committee opted to focus on other cities with significant military headquarters and industrial centers. Hiroshima stood as a major base of operations in the Japanese defense effort. Nagasaki was one of the country’s key seaports. Both places were wartime manufacturing hubs.

4. The USS Indianapolis's secret mission ended in the worst naval disaster of World War II.

Components of the 9700-pound nuclear fission bomb nicknamed Little Boy, destined to be dropped over Hiroshima, were delivered in secret to an American air base in the Northern Mariana Islands by the USS Indianapolis. After dropping off the materials, the Indianapolis was torpedoed by Japanese submarine and quickly sunk just after midnight on July 30, 1945.

Around 300 crew members immediately went down with the ship. The remaining 900 men floated at the surface, awaiting rescue. They endured dehydration and hunger, hallucinations, salt poisoning, and frequent, vicious shark attacks. By the time rescue came on August 2, there were only 317 survivors.

On August 19, 2017, a research team led by Microsoft co-founder Paul Allen located the wreckage of the Indianapolis on the bottom of the Philippine Sea, 3.4 miles below the surface.

5. The number of victims in Hiroshima and Nagasaki is still unknown.

At 8:15 a.m. on August 6, 1945, Little Boy exploded over Hiroshima. The blast's yield was equivalent to 15,000 tons of TNT. “What I felt at that moment was that Hiroshima was entirely covered with only three colors. I remember red, black, and brown … but nothing else,” recalled Akiko Takakura, an eyewitness who was then 20 years old. In minutes, dark smoke climbed nearly 4000 feet into the air. More than 90 percent of the city’s structures were damaged or destroyed.

Nagasaki was hit with an implosion-type plutonium bomb (called Fat Man) three days later. The blast’s effects—equaling 21,000 tons of TNT—were felt over an area of 43 square miles.

According to the U.S. Department of Energy, “No one will ever know for certain how many died as a result of the attack on Hiroshima.” The same goes for Nagasaki. Patchy census records, the obliteration of government buildings, and other factors make it impossible to get at exact figures. The initial blasts are estimated to have killed 70,000 in Hiroshima and 40,000 in Nagasaki, not including those who later died of radiation poisoning or other injuries.

6. The Soviet Union declared war on Japan less than a month before World War II ended.

At the Allies' Tehran Conference in November 1943, the Soviet Union had agreed to declare war on Japan three months after Germany's surrender to force an end to World War II while retaking occupied territory from Japan. That day came on August 8, 1945. About 1.6 million Soviet troops were swiftly dispatched to Japanese-occupied Manchuria (modern-day northeastern China). The USSR inflicted heavy losses during their engagements with Japanese forces in China, Korea, and the Kuril Islands.

7. Japan formally surrendered aboard the USS Missouri, ending World War II.

A crowd celebrates V-J Day and the end of World War II in Times Square.Dick DeMarsico, World-Telegram, Library of Congress // No Known Copyright Restriction

On August 14, 1945, Emperor Hirohito announced Japan's unconditional surrender to the Allies. The news rocketed around the world, launching joyous celebrations, parades, and patriotic displays to mark V-J Day. On September 2, aboard the USS Missouri, Japanese Foreign Minister Mamoru Shigemitsu and General Yoshijiro Umezu signed the official Instrument of Surrender document crafted by the U.S. War Department. Also present was General Douglas MacArthur, Supreme Commander of the Allied powers.

“It is my earnest hope and indeed the hope of all mankind that from this solemn occasion a better world shall emerge out of the blood and carnage of the past,” MacArthur told the gathered crowd. The USS Missouri would go on to participate in both the Korean and Persian Gulf Wars before it was decommissioned for the last time on March 31, 1992.

8. The pair in the iconic Times Square kiss photo, taken on V-J-Day, didn’t know each other.

Titled “V-J Day in Times Square,” the picture was snapped by Alfred Eisenstaedt for Life magazine. Since Eisenstaedt didn’t write down the couple's names, their identities were a mystery for decades. Then Lawrence Verria’s 2012 book The Kissing Sailor: The Mystery Behind the Photo that Ended World War II seemed to put the matter to rest: It pegged George Mendonsa and Greta Zimmer Friedman as the couple.

Except they weren’t a couple at all. Mendonsa was a sailor on a date with his future wife at the time. Upon hearing the news of Japan’s surrender, he excitedly grabbed Friedman—a dentist’s assistant he didn’t know—and planted a kiss on her lips. Unfortunately, Friedman wasn't into it. “It wasn’t my choice to be kissed,” she later said. “The guy just came over and grabbed!”

9. Frustrated soldiers in the Pacific theatre waited months to return home.

The United States couldn’t immediately bring all of its soldiers home once the Axis Powers surrendered. And that created plenty of tension overseas. Rep. Clare Boothe Luce, a member of the U.S. House of Representatives from Connecticut, said on September 17, 1945 that every congressperson was “under constant and terrific pressure from the servicemen and their families” who wanted swift discharges.

Servicemembers stationed in Japan and the Far East began stamping the phrase “No Boats, No Votes” onto their homebound letters—indicating that if they didn't get picked up soon, leaders would hear about it in the following year’s congressional elections. Four thousand homesick troops held a mass protest in Manila on Christmas Day. Similar demonstrations took place in London, Paris, and Frankfurt.

10. The last World War II Japanese internment camp in the United States closed in 1946.

Around 120,000 people of Japanese ancestry were imprisoned in internment camps across seven U.S. states beginning in 1942. President Franklin D. Roosevelt authorized the detention of Japanese-Americans regardless of citizenship status or loyalty to ensure "every possible protection against espionage and against sabotage" following the Japanese attack on Pearl Harbor. The last of these camps, located in northern California, stayed open until March 20, 1946.

11. Some Japanese soldiers kept fighting long after the end of World War II.

Second Lieutenant Hiroo Onoda was 23 years old when he was sent to Lubang Island in the Philippines on December 26, 1944. He and three enlisted men would remain there years after the war ended. Disbelieving reports of Japan’s defeat, the soldiers regularly fought with islanders they mistook for enemy combatants. One of Onoda’s comrades surrendered in 1950 and by 1972, police officers had shot the other two.

Lieutenant Onoda didn’t give up until after he was rediscovered by a Japanese traveler in 1974. A delegation including one of Onoda’s former commanding officers came to Lubang later that year to accept his surrender.

Two additional holdouts, Shoichi Yokoi and Teruo Nakamura, remained hidden elsewhere in the former Pacific theatre until 1972 and 1974, respectively.

12. Only one state officially celebrates the end of World War II.

Rhode Island is the only state in the union that celebrates the end of World War II as an annual legal holiday. Victory Day falls on the second Monday of August.