A duck walks into a pub and orders a pint of beer and a ham sandwich. The barman looks at him and says, "Hang on! You're a duck." "I see your eyes are working," replies the duck. "And you can talk!"...
On a number of vehicles I've driven I hear an electric motor/pump running for a few minutes after switching off the ignition and stopping the engine. I always thought it was an oil pump supplying oil...