A knife should be attached to the end of your rifle.
Story I heard from a veteran friend during bayonet training.
Instructor: If your bayonet gets stuck in your opponents body, firing a round will usually dislodge the bayonet.
Private: Sergeant, if I still have a round in my weapon, why am I using the bayonet?
Instructor: Private! Push-Ups! Lots of Push-Ups!