If you hear weird stories or see strange things on Monday, be suspicious. It’s April Fools’ Day!

Lots of people get into the spirit of fun on April 1. Your family and friends might play silly tricks. Even serious groups such as NASA and the news media play tricks that day.

The important thing to remember is that April Fools’ Day tricks should all be friendly. If someone could be embarrassed or hurt, it’s not funny. And it’s not in the spirit of April Fools’ Day.

The Mini Page talked with an expert on community rituals, or customs, to find out more about this holiday that’s all about fun.

Who thought of this, anyway?

Many cultures have a day for fun and jokes, and often those days come in the early spring. Experts believe April Fools’ Day may have started in France in the 1500s.

At that time in France, many people celebrated the new year around April 1, at Easter time. In 1564, the king moved the new year to Jan. 1. A new calendar was developed in 1582.

When the calendar changed, people got confused. There were no daily newspapers, Internet or TV back then. It took a while for news to get around.

People who hadn’t heard the news showed up on April 1 for New Year’s celebrations. Those in the know called them fools and played tricks on them. For example, tricksters would send them to New Year’s parties that didn’t exist.

April Fish

The French call April Fools’ Day Le Poisson d’Avril (PWAW-sown dah-VRIL), or April Fish. Experts are not sure why fish became part of April Fools’ Day. Some believe it’s because young, inexperienced fish are easily caught.

On April 1, French kids stick pictures of fish on people’s backs.

Last year on April Fools’ Day, Kodak employees announced a new product, a printer that could print live kittens. They claimed a large-format printer that could print out live elephants was coming in 2013. On April Fools’ Day in 1996, Taco Bell put out an ad claiming the company had bought the Liberty Bell. The ad said they planned to rename it the Taco Liberty Bell. Thousands of people believed the joke and called to protest.