Patricia: During Japan' s Tokugawa period, martial arts experts known as ninjas were trained for the purposes of espionage and assassination  Yet at that time there was actually very little ninja activity in Japan, and most Japanese did not fear ninjas  Tamara: That is not true
Many wealthy Japanese during the Tokugawa period had their houses constructed with intentionally squeaky floors so that they would receive warning if a ninja were in the house
As part of their secret training, ninjas learned to walk on squeaky floors without making a sound.