1st April is a day to be careful, or you could easily get tricked by someone. It’s April Fool’s Day, a day when people traditionally like to try to make a fool of someone else and laugh at them. (来源：EnglishCN.com)

There are lots of theories surrounding the origins of the day, but one explanation is connected with the change in the calendar in the 16th century, which meant that 1st April was no longer the beginning of the year. Those who still celebrated the New Year on 1st April were called fools.

So what kind of pranks do people play on April Fool’s Day? Well, there are lots of simple tricks that you can play on your friends. For example, you could wear a black sweater and pull a piece of white thread through it, so that people try to pull it off. You could change the time on someone’s alarm clock so that they’re late for work. Or glue a coin to the floor and see how many people try to pick it up.

All these are small-scale practical jokes which you might play on one other person or a few people. But there’s also a tradition of large companies attempting to fool a lot of people. For example a burger restaurant once claimed that they were introducing a left-handed burger!

In particular, the media often try to make people believe something which is not true. Newspapers publish some ludicrous stories every year, although some of them are actually true. It’s entertaining to try to guess which stories are true and which are fake. In the April Fool’s stories, they often include a clue to the fact that it’s a joke. For example the name of an ‘expert’ quoted in the article might be an anagram of ‘April Fool’.

Radio and television programmes have also fooled many people by broadcasting reports which are untrue. One programme announced the invention of an amazing new weight-loss product - water which contained minus calories!

And one of the most famous hoaxes ever was broadcast by the BBC itself in 1957! A very serious news programme called Panorama reported on the poor spaghetti harvest in Switzerland, and showed pictures of farmers picking spaghetti from trees! Hundreds of people were taken in and wrote to the BBC asking how to grow their own spaghetti.