It's summer and the kids are bored at home. You need something for them to do.
One idea is to take traditions from other times of year and update them. Like creating a candy tree. My cousins used to play this trick on me when I was little around Easter time, but it also can be done at other times. After all, trees tend to fruit during summer and fall.
Have you ever noticed how much fun kids have just messing with sidewalks? If you live in an older neighborhood, or just have an older sidewalk, you can encourage the kids to be "Sidewalk Archaeologists" and collect the dates and info from the medallions that each concrete company impresses on a sidewalk or driveway when they pour it.
Finally, don't forget to mix the fun of nature with the pure joy if naughtiness. You and your kids can engage in some guerilla gardening by making seed bombs. These are little nuggets of degradable paper and wild flower seeds that you can surreptitiously toss into ugly vacant lots and other such places.
(And yes, these are backlinks. More about this next post.)