Instructions
Hold down the weapon-select button, and choose the Rivet Gun.
Aim at a wall or ceiling, and fire to place a trap rivet.
Place the rivets in places that the enemies will pass naturally, such as chokepoints like doors and narrow hallways. Be sure to place the rivet at body/head level for an effective attack.
Draw the enemies' attention, and lead them through the chokepoint to the rivet sensor. When they pass through, the rivet will fire, doing damage.