Stakeouts in cold weather are no fun, especially without kairo, the disposable heat packs we use today. Instead, of kairo, ninja used a donohi. This device was pretty simple, but very effective. They would put a flammable material (gunpowder, alcohol, etc) in a copper or iron cylinder, or even bamboo, and light it. The fire could last for hours or even days, far longer than any kairo now!

Could ninja walk on water? Researchers can’t really prove it, but they think this tool, mizu-gumo (literally, water spider), which consisted of four curved wooden or inflated animal hide pieces strung together with a fifth piece in the middle, may have been used for water-walking. Perhaps they couldn’t use them to walk over deep moats surrounding castles, but they were probably useful in swampy areas.

Ninja may have used cat eyes and cat hands, but even they weren’t able to harness the stealthiness of felines. As smooth as ninja were, cracking twigs, crunchy snow or even the mere silence of the insects when a human comes near, could give the ninja away. To prepare for this, they sometimes carried a cage of crickets and secret poisons that either made the insects chirp, in order to cover-up the sound of movement, or be silent when need be.

What would you do if you were a ninja about to be captured by the enemy? How about throwing eggshell bombs—aka Edo Period (1603-1868) pepper spray—at them? The trick is to poke a hole in an egg, drain the contents, and then refill it with iron filings, salt, pepper or anything else that would cause irritation to the eyes or nose. Since eggshells are easy to break, throwing them at your opponent would quickly release the blinding substance. We're interested to know how they transported their egg bombs without breaking them along the way.

To the ninja, rice was more than just breakfast, lunch and dinner; it was used for a code system. Rice could be painted different colors and arranged in certain combinations or amounts to convey secret messages. When left on the side of the road, a fellow clansman would see the sign and understand the message, but the average joe would just see some rice. Pretty creative, unless someone ate the rice!

Harnessing the power of nature, getting creative with everyday items and using what would probably have been state-of-the art technology at the time, ninja were actually way cooler than we previously thought—and that’s saying a lot. Technology may have made most of these tools obsolete, but some could easily still be used today.

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