I heard a version of this originally at Ft Leonard Wood, Missouri, when I was there for Army Basic Combat Training as a member of A Company, Third Infantry Battalion, Tenth Infantry Regiment--which is sort of long-winded, so we just said Alpha-Three-Ten. We had drawn weapons and then marched out as a company to a large open area. One of the drill sergeants was carrying a couple of blue milk crates (the sort that say "Thou shalt not steal" on the side) filled with something I couldn't see. Another carried what turned out to be a portable PA system. Amidst many curses--by which we divined that something possibly dangerous was about to happen--the drill sergeants spread us recruits out until each of us was slightly more than two arms' lengths away from anyone else. Then the drill sergeant with the milk crates began to distribute what he had in them--bayonets.
Once that had been done, the PA system having been set up in the meantime, a drill sergeant lectured us on the proper things to yell. Every move with the bayonet would be accompanied by the shout of "Kill!" Occasionally, the question would be asked over the PA, "What makes the grass grow?"--to which of course, the correct answer is "Blood! Blood! Bright red blood!" followed by the appropriate form of address for the one who'd asked the question--usually, "drill sergeant," but occasionally the company commander (who was a woman) would come out and it would be "ma'am."
Then they taught us to "fix bayonets" and taught us another question and answer: "Why is the sky blue?" "Because God loves the infantry!"