If there is a loud drumming of the shields with the assagai, an attack is sure to come. Form ranks!
Also, if there is a loud beating of the Arisaka stocks on the ground, an attack is sure to come. Check the 1919's!
Seriously, this is a great post and something of interest, I have always felt situational awareness often gets overlooked in the gun culture, it does does not have the glamour of fancy new hardware.