When a ninja has mastered the arts of night stealtage and has gained the use of all 6 senses (including the psychic abilities they gain through deathly training), they are able to go out and ninja in the night without worrying about jerks spotting them.

1) To go out and ninja in the night.
2) To pork a girl, at night(or somewhere dark), with blinding speed.
3) To frolic amongest the treetops.