From "The Good Life France"

"Meanwhile, today (if you're reading this on Saturday 1 April) is April Fool's Day which in France is known as April Fish Day because it's customary for kids (mostly) to stick a paper fish on your back. Apparently it's hoped that you'll walk around all day unaware of people tittering behind you! There are occasionally some fun prank stories in the papers but on the whole they're a bit lame. The best one I recall is reading that the French Government were going to make it law to carry a picnic basket in your car alongside the usual paraphernalia such as high-viz jacket and spare bulbs. It was claimed the emergency picnic basket had to contain a bottle of wine, cheese and a baguette plus of course, a red and white check tablecloth. With all the madness that's going on in the world today, that's a law I could definitely get behind!"

I agree...we've had many such picnics in our life.