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.