April the first is always a fun time to be a teacher; the students get you and you get the students. Many years ago I taught 4th grade at Sefton Park School in Bristol, England and every April 1st the students would do something neat. One year they turned my wonderful antique kneehole teacher's desk around before I arrived at school so that I couldn't open the drawers. Another time they all started stroking their chins when I walked into the classroom in the same way I stroked my beard. I would always get them back of course. One of the more memorable Tricks was to give them a thirty minute lesson on how spaghetti grew on trees. I would draw a tree with the spaghetti hanging down in large clumps and tell them how it had to reach a yard long before it was harvested. I would draw a harvesting tool on the board that looked like a piece of wood that turned up at the end where the spaghetti would rest when it was ripe and the right length. It was then cut with a large pair of shears. We would talk about the right climatic conditions for it to grow in Italy and other Mediterranean countries. A the end I would write April Fools on the board and the students would laugh and throw their papers at me.
Today, School Spring, the organization that helps people get teaching jobs, sprang a wonderful April Fools stunt by advertising a job opening at Hogwarts, the school attended by Harry Potter.