For me, I would have to say it is the cockroach. They hide out during the day so you cannot see them. They creep out at nighttime just to invade the privacy of your home without you knowing.
With a midnight trip to the bathroom and a sudden switch of the lights, you may find a little visitor entertaining you. The cockroach might laugh at you as it sees you scream and jump in the air yelling, "AHHHHH! A COCKROACH!"
They are sneaky little fellows that never seem to die. All they do is sit in a dark quiet place and await the next time they may startle an unsuspecting HUMAN!