April Fish!

Poisson d'avril, or 'april fish' is, quite right, the Belgian way of saying April Fools. There's a long story about how it dates back to ancient times but long story short, for those who play jokes they say "april fish" and the typical little kids play joke is to stick a fish on people's back. However I did notice that there weren't many fishes swimming around april 1st. April fools, as with Hallowwen (and Thanksgiving, shockingly), seems to be much more popular in the US than over here.