|Swiss Spaghetti Harvest|
Well, it's more complicated then you might expect. Have a look at Credo for a good summary of the history of April Fool's Day.
Media hoaxes are a popular way to entertain and take advantage of the gullibility of the public on this day.
April Fool's Day is also a timely reminder to check your sources carefully before you enthusiastically quote them.
The Evaluating sources LibGuide and the Info Skills Road Trip have some great points to consider before you hand your assignment in.