A Englishman, a Irishman, and a Scotsman sit down at the bar and order a beer. The barkeep sets a draft in front of each and three flies land, one sitting atop each pint.

The Englishman sees the fly, pushes away the glass, and says "I can't drink this, it's been contaminated."

The Irishman flicks the fly off the top of his beer and drinks half the pint in one swallow.

The Scotsman picks up the fly from his beer and shouts at it, "Spit it out, spit it out you bastard!"