Mick, from Dublin, appeared on “Who Wants’ to be a Millionaire?” & towards the end of the program, had already won $500,000.   

You’ve done very well so far” said Eddie, “but for a million dollars you’ve got one Lifeline left, “Phone a friend”.  “Everything is riding on this question, will you go for it?”
“Sure,” says Mick “I’ll have a go!”

“Which of the following birds does NOT build its own nest?”    (a)   Sparrow    (b) Thrush  (c)   Magpie   (d)   Cuckoo

“I haven’t a clue” said Mick, “so I’ll use my last lifeline & phone my best friend Paddy back home in Dublin.”
Mick called up his mate & told him the circumstances & repeated the question to him.
“Hell, Mick!” cried Paddy “Dat’s simple, it’s a cuckoo.” 
“Are you sure?”
“I’m really sure.”
Mick hung up the phone & told Eddie, “I’ll go wit Cuckoo as my answer.”
“Is that your final answer?” asked Eddie.
“Dat it is.”
There was a long, long pause & then Eddie screamed, “Cuckoo is the correct answer, Mick, you’ve won 1 million dollars!”

Later, Mick invited Paddy to their local pub to buy him a drink.
“Tell me Paddy, how in heaven’s name did you know it was da Cuckoo that doesn’t build its own nest?”
“Because he lives in a #### Clock!!”