Ah, the Irish; so logical and smart

Forwarded by one of Rico's friends, this splendid Irish joke:

Mick, from Dublin, appeared on Who Wants To Be A Millionaire and, towards the end of the program, had already won 500,000 pounds. "You've done very well so far," said Chris Tarrant,the show's presenter, "but, for a million pounds, you've only got one life-line left: Phone a friend. Everything is riding on this question... Will you go for it?"
"Sure," said Mick. "I'll have a go!"
"Which of the following birds does not build its own nest:

a) the sparrow
b) the thrush
c) the magpie
or
d) the cuckoo?

"Haven't got a clue," said Mick, "so I'll use me last lifeline and phone me auld friend Paddy, back home in Dublin."
Mick called Paddy, told him the circumstances, and repeated the question.
"Fookin' hell, Mick!" cried Paddy. "Dat's so simple; it's da cuckoo."
"Are you sure?"
"I'm fookin' sure."
Mick hung up the phone and said to Chris: "I'll go wit' cuckoo as my answer."
"Is that your final answer?" asked Chris.
"Dat it is, sir."
There was a long, long pause, and then the presenter screamed: "Cuckoo is the correct answer! Mick, you've won one million pounds!"
The next night, back home in Dublin, Mick invited Paddy to their local pub to buy him a drink. "Tell me, Paddy, how in Heaven's name didja know it was da cuckoo what don't build its own nest?"
"Cause he lives in a fookin' clock, ya idjit!"