10 Stealthy Facts About Ninjas.br In honor of International br Ninja Day, here are ten facts br about the mysterious warriors.br 1. Ninja were known for br their skills in guerrilla warfare, br assassination, sabotage, br espionage and infiltration.br 2. Though secretive, ninjas br adhered to a strict hierarchy br that eventually evolved into br larger territorial guilds.br 3. Ninjas were a hero to the br lower classes in Japan, often br recruited by those unable to afford br the services of the upper-class samurai.br 4. Because they didn't carry br large swards, Ninjas often used br whatever was available as a weapon.br 5. Employing secrecy as a means br for survival, ninjas also encouraged br exaggerated tales of their exploits br as a means of intimidation.br 6. Ninjas dressed in all black is br a modern day conception. Ninjas br did their upmost to blend in to the br surroundings of their assignments.br 7. Part of ninja training included br an in depth knowledge of various forms br of medicines, including a mysterious br "black medicine" used to stop bleeding.br 8. Ninjas used little "smoke br bombs" of ash contained in an br eggshell to create confusion br or misdirect their enemies.br 9. Female ninjas were common. br They often used their hair pins br and nail attachments as weapons.br 10.