Nice, TG! The cheeks are definitely puffed out when the flp is extended - after all, it's the air pressure in the mouth that keeps it extended. Removed pressure lets it roll up again. Same principle as blowing a trumpet - the air pressure creates the noise. Is it Dizzy Gillespie gets those HUGE cheeks when he blows? Norbert - Originally for scaring mice? Wow, that's some cool trivia! :] Fish