1. War Pigs The oldest recorded use of animals in warfare was to basically loose them, starving and craven, upon the enemy. Pigs were ideal for this as they were easily directed and fairly ravenous. Later, in the 3rd century BC, the Romans would use squealing pigs to terrify Phyrrus' war elephants into stampeding their own troops. In another Roman instance of pig warfare, the Romans apparently came across a sturdier breed of elephant, but quickly solved the problem: lighting the pigs on fire before they released them on the enemy.

2. Elephant Cavalry About those elephants. The Romans weren't the last to meet the pachyderms on the battlefield. Not by a long shot. Everyone from Siam to Greece used them in antiquity. They were even used right up to the end of the 19th century, both as command centers and artillery mounts. Sure, they were easy targets for artillery, but muskets weren't much use against them. The elephant doubled as both mobile command center and tank. Everything from rifles to cannons to Gatling guns was perched upon their broad shoulders, to devastating effect.

4. Bat Bombs Not to be out-done by the Soviets, the Americans also explored the ol' "exploding animals" routine. The idea was to attach small incendiary devices to whole colonies of bats, pack them in a crate and parachute them over Japan. When their crates opened, the bats would find trees and barns to take up roost in, and then BOOM: fires are started simultaneously across miles of country. Dubbed "Project X-ray", the concept actually made it to the test phase. 30 test were run, and the most (un)successful one of these was an accident during which bats burned down a hangar — and a commanding officer's car.

5. Night Vision Glow Worms Not every animal dispatched during war time was a kamikaze. Glow worms were more your spec ops teams. During WWI, they were deployed by the British in trenches and on night sorties. Their tiny, glowing posteriors provided light "in dark places, where all other lights go out." Wait, that was the Light of Earendil in Lord of the Rings, which was inspired by Tolkien's experiences in WWI — but I digress. Glow worms allowed soldiers to read orders, maps and communications without being seen by the enemy. Not bad for a bug.

6. Bomb-detecting Sea Lions Another spec ops squad are the currently-deployed U.S. Navy sea lions. They are tasked with both searching out enemy mines and intercepting enemy divers. But the sea lions' tricks don't end there. If they do intercept an enemy combatant, the sea lion is trained to harass said interlopers. They'll even pursue bad guys onto land, barking all the while to alert U.S. troops to the presence of danger.

8. Mine-sniffing Rats There are mines on land, too. But don't worry, animals have them covered as well. Enter the humble rat. Sure, he's less glamorous than a porpoise, but he can find a mine just as easily. Even in tight, hard-to-reach areas. Rats also require less resources to train than larger animals, and the same goes for food and transportation. On a less upbeat note, rats aren't exactly hard to come by, and losing a few to land mines is seen as less tragic than losing a dog (or dolphin).

9. Fear-smelling Gerbils Like tiny fuzzy Diana Troys, gerbils can sense how you feel. Specifically, they can smell if you're afraid or have more adrenaline coursing through your system than normal. MI5 once sought to harness the power of the gerbil for good. They meant to sniff out weapons smugglers, terrorists and drug stashes. Unfortunately the gerbils couldn't tell whether you were smuggling bombs or just afraid of flying, so the program was scrapped.

10. Bomb-detecting Bees The smallest of our explosive detectors is also the most specialized. The common honeybee has a sense of smell equivalent to that of a dog and can be trained in a matter of minutes. Honeybees are trained to detect a single type of explosive, narcotic or chemical weapon, and are then mounted in tiny harnesses within a detection unit. Multiple groups can be housed in the same unit, creating a bomb-detection hive of sensor-bees. Deployable at checkpoints and in inspections of suspected terrorist bunkers, bees are some of the best sniffers in the bomb-detection biz.

11. Cyborg Beetles Insects are going on the offensive as well. Small enough to go undetected, beetles are outfitted with video and audio equipment and loosed upon surveillance targets. The beetles are part of a new breed of military drone, dubbed MAVs (or micro-air-vehicles). Because the beetles are living organisms, they can actually act as batteries for their equipment. The beating of their wings recharges the batteries, much like the brakes on your hybrid car. Rumor has it that some even have offensive capabilities in the form of poisonous injections and tiny embeddable GPS tags.

12. Pigeon-guided Missiles Need a bigger bang than a beetle can deliver? Back in WWII, scientist B. F. Skinner came up with Project Pigeon. Skinner was the pioneer of positive and negative reinforcement animal training, and here's what he did with it: he outfitted missiles with nose-cones that doubled as pigeon houses. The pigeons were trained to peck at little windows when their target came into view, guiding the missiles. The project actually proved reliable, but was superseded by electronic targeting systems before it could be implemented.

13. Chicken Nukes Still not enough of a bang? Well, the U.K. once developed a device that delivered the ultimate boom for your birdy buck: nuclear landmines. This Cold War project called for the 10-kiloton mines to be buried around West Germany. The problem was keeping the circuitry working through the cold of winter. Enter the chicken — literally. Chickens were housed within the mine casings and given enough food to last the winter. And so a chicken's body heat would enable a WMD. Happily politics got in the way, and these were not deployed.

14. Camel Artillery Similar to elephants, camels were once used to carry armed troops into battle. Their role began as a sort of slow, ornery cavalry unit. But as that became less and less effective against horses, camels shifted roles. Gatling guns, canons and other heavy weapons were mounted hump-side, and the camel became a mobile artillery placement. The camel's famous survivability in desert climates also aided it's continued use, even elevating it to royal-guard status in 19th century Persia.

15. Spy Cats I'm giving this one an "honorable mention" status. Project Acoustic Kitty was a planned CIA operation which used cats as listening devices. The problem was that they, uh, used cats. Their first test subject was a grey tabby. She took to the equipment fine, and if she was placed indoors, could basically navigate to the right areas. The problem was using her outdoors, where anything and everything had the potential to distract the CIA cat — and did. All told the project cost $20 million, deployed one cat on one mission, and saw her hit by a car before she even reached her intended targets.

16. Bomb-sniffing Mice Another entry for the maybe pile is the bomb-sniffing mouse. Mice have better olfactory senses than dogs (or bees) and so seem the ideal candidate for sniffing out a bomb. Groups of mice could be trained to fear the presence of explosive materials, to be implemented in airports or other stationary checkpoints. If the mice were to run into their "home" out of fear, alarms would sound. Now, even a CIA cat knows scaring a mouse isn't that rough a job to accomplish, but the real chore would be the constant training and short working life of each mouse — a mere 18 months.

17. War Bears Wojtek the army bear sounds way cooler than he actually was. When I heard of him, I thought gun-toting man-mauling badassery awaited me. His name even means "he who enjoys war," But, no, he basically just schlepped artillery around, smoked cigarettes (not the safest habit to pick up around the explosives) and lived in a stinky box. Nonetheless, Wojtek actually earned the rank of Private and was listed as a member of the 22nd artillery supply company in the Polish army. I suppose that's pretty good for a bear.

3. Anti-tank Dogs Had elephants continued on as tanks, they would likely have run into one of the strangest anti-tank weapons ever deployed: man's best friend. In WWII, the Soviet Union deployed mine-laden pups in an attempt to disable German tanks from below. The dogs were starved and taught that food could be found underneath tanks. A few tanks were disabled this way, but, sadly for the Soviets, half of these were their own. Worse was that the dogs had not been trained around gunfire, and often ran fearfully back to their trainers, exploding amongst the Soviet ranks. Of course, the dogs had it the worst of all.

7. Dolphin Mine-sweepers Not to be out-done, dolphins are out there sweeping for mines right alongside their sea lion compatriots. They've even been at it longer, since the Cold War. Dolphins have an advantage over the competition in that they are faster in the water and are equipped with sonar. They also have a special trick up their flippery sleeves when it comes to enemy combatants: GPS shackles, tricked out to inflate upon being attached to a diver. The enemy goes bobbing up to the surface, and the dolphin continues his duties.