This seems like quite a normal Funny YouTube Animal Video until... well, until the French bulldog opens its mouth.
Because the sound he produces is not unlike... well, put it this way: remember when Sigourney Weaver becomes possessed by Zuul in 'Ghostbusters'?
Presumably this dog's trick works because the sound is so horrifying that his owners have to immediately open the door.
Ah, little doggy. If only you were as smart as this cat!
(Via Tastefully Offensive)