There was once a very stupid parrot that could only say: “Who’s there?”
So one fine evening, while its owner was out shopping, the gas delivery man arrived at the door. He pressed the door bell and waited for the door to be opened.
At that moment, the parrot said: “Who’s there?”
The man then promptly replied: “Gas delivery man.”
The parrot then spoke: “Who’s there?”
The man then repeated himself again.
After several hours, the owner returned home. He was shocked to find a man outside his door, foaming in his mouth.
Puzzled, he said:” Who’s that?” A voice from inside the house replied: “Gas delivery man.”