When I picked my fun-loving 4-year-old up at preschool yesterday, she greeted me with, "Mama! April first is tomorrow! We can fool people with jokes and make people laugh! More than normally!"

I've never been one for pranks, but I love a stupid joke or a tricky riddle. I've always wondered why April 1 is linked with silliness; thanks to a little easy internet sleuthing, I discovered that April Fool's Day has been taking place in France since the late 1500s, when Pope Gregory XIII switched from the Julian calendar, which celebrated New Year's Day in the springtime around April 1, to the Gregorian calendar, which dictated that the New Year began on January 1. Those who disregarded the change -- or who hadn't heard about it -- were called fools and were tricked into going on "fool's errands."

(Of course, there are loopholes in that explanation, most historians say, though it seem to be the most plausible of the bunch. For more theories, click over to the Museum of Hoaxes).

Regardless of its origin, April Fool's Day is celebrated in different days in different countries -- in Scotland, for instance, the jokes have to do with one's backside, the day is called "Taily Day," and the classic "Kick Me" sign reigns supreme. In England, the rules are that jokes can only be played in the morning. And in the US, of course, pretty much anything goes.

If you're looking on some fun ways to celebrate (harmlessly!), here are a few options:

Elephant jokes. What cheers you up when you are sick? A getwellephant card.

Knock Knock jokes. This collection is full of clean -- and pretty funny -- jokes.

Brainteasers. Palindromes, puzzles, and more.

Harmless pranks. Practical jokes are always tricky. You know your kids best, so pick ones that suit your family. The ones at this site are really tame.

Riddles. What can you catch but not throw? (A cold!)

What's your favorite April Fool's joke, practical or otherwise? Please share in the comments!

Lylah M. Alphonse is a Globe staff member and mom and stepmom to five kids. She writes about juggling career and parenthood at The 36-Hour Day and blogs at Write. Edit. Repeat. E-mail her at lalphonse@globe.com.