A college buddy of mine dated a girl whose cat had a unique talent.
She found out about it because one day she was regaled by questions about why her outgoing message was "Meow, meow, meow, meow...."- everyone thought it was cute but odd. Thinking that the cat had accidentally pressed the button and recorded itself, she went home and recorded a new, standard message.
Later that evening, as she and my buddy were watching TV, the cat jumped up on her desk, went to the machine, bent over the microphone and pressed the record button..."Meow, meow, meow, meow..."
It seems the cat liked the sound of its voice, and learned from watching her (and, presumably, trial and error) which button to press. That way, when everyone was gone and the phone rang, the person on the phone AND the cat heard the meowing message!