a way to notice a nano is if your opponent is quickly scrolling through all the player and if he shifts the line. then, if you notice he's shifting through linebackers or safeties, and placing them in-between certain members of the D-line, it's probably a nano blitz, so snap the ball quick and be ready to pass as quick as you can. be careful though, because if your opponent has already done a couple nanos, they could just set-up like one is coming, then drop back into coverage.