Believe it or not, your kids have probably been saving up their mischief all year long to prepare for the annual April Fool's Day fun. There's nothing new about this holiday created back in the 16th century, except maybe the way you celebrate it. For children, April Fool's Day provides the opportunity to get away with being devilish within reason. But before you set your child loose, it's important to lay the ground rules for April 1. For starters, you want to stress that April Fool's Day pranks should be merry, not mean-spirited. The last precedent you want to set for your kids is that it's okay to be cruel, even for one day of the year. You want your kids to understand that the intent of an April Fool's Day gag is not to be hurtful. Perhaps the best way to set an example for April Fool's is to play your own pranks. Here are some great ways to get them fooled. Start the day off by adding food dye to your child's milk. Turn it a shade of green, blue or red.