Adolph Isaacsen, All about Ferrets and Rats
“ A mouth-harmonica seems to be the rat's favorite musical instrument, and its gentle strains exert the most power over him, far more than the tones of any other instrument. If the music be soft, mild, and pathetic, the rat will listen and come very near, for he is a very susceptible sort of beast, and, if closely observed, tears of sorrow, or of sad and tender reminiscence, will be seen coursing slowly down his cheeks. ”
