I captured the Riddler sneaking around the Batcave. When I told him to never to snoop around the Batcave again, he made me solve this riddle first:
"When Miss Millie purchased her new parrot, the salesman assured her that it would repeat any word it heard. About a week later, Miss Millie returned the parrot complaining it hadn't uttered a single word. Given that the salesman had spoken the truth about the parrot's abilities, why wouldn't the bird talk?"
Answer: The parrot was deaf.
I will release the Riddler from custody asap.
Frieza