When I was in high school in Florida, I used to chew gum ferociously.

My calculus teacher, a nun of approximately 97 years of age who had almost samurai-like skill with a wooden ruler, would see red whenever she'd spy a student with a mouth full of gum. She whipped across the room, a blur of black and white, rapping knuckles so hard that the student either swallowed his gum or sucked it down into his windpipe. She had no real preference.

Afraid of swollen knuckles and unsure of how to self-administer the Heimlich maneuver, I'd pause before class each day and stick my gum on a chain-link fence next to the tennis courts outside her room.

Twenty-five years after high school graduation, I happened to be in that town again on business, and I wandered around my old high school. When I got to the fence, I found it covered with thousands and thousands of pieces of gum, some I'm sure dating back to my day, with more added each year. It had become some sort of school tradition, all based on my fear of a little woman with a 12-inch stick and ninja-like speed.

As an adult, I try to make sure that my kids never, ever, get their hands, or their teeth, on gum. I tell them it's because I worry about their teeth, but it's really because I know that if I give them a piece, sooner or later I will find it in the carpet, pressed against a wall, in the hair of a kid or even stuck to the tail of the family dog. I've found gum stuck to the TV set, under the kitchen table and to the roof of my car.

Nothing makes me angrier than finding a piece of chewed gum permanently affixed to someplace it shouldn't be. (Well, as my kids will tell you, a lot of things make me that angry, but that's just me.) Whenever I do find a leftover solidified lump somewhere in the house, I line kids up and threaten that unless I find out who did it, they're all going to have to chew it.

This never works, of course. My kids have become masters at maintaining a solid front of denial. None of them know anything about it and, as a group, have no comment. They've perfected that frozen stare that betrays no emotion whatsoever. They look, in fact, as if they've all had extensive Botox treatments.

The only thing left, I suppose, would be to take dental impressions of each child and keep them on file, but that would probably involve giving them gum, defeating the whole purpose.

Part of it is our own fault. My wife and I have warned the kids, as we were warned growing up, that swallowed gum will stay in your stomach for seven years. We know that there's no science to back this up. But with five kids, you have to cut back on entertainment expenses, and sometimes messing with the kids is a cheap thrill.

I still chew gum myself, but only in my own car, where the kids can't see me. I hide the pack in the ashtray where the kids will never look. (Don't worry. There's no danger in revealing this here, as my kids, like millions of other Americans, have shown no interest in reading this column.)

The other day, my wife and I took our daughters to another city to visit relatives. We thought it would be nice to take them to an art museum, to see a historical area and maybe out to a fancy restaurant.

The highlight of the trip for them, however, was a tree outside a shoe store covered almost entirely with stuck-on bubble gum. The disgusting display had almost completely obliterated the bark and clearly had been the result of decades of regular contributions. The earliest pieces had gone black with age and had been covered with newer layers. It could be, 100 years from now, a case study for an archaeologist who wanted to document the decline of our society by analyzing generations of DNA.

"Ewwww!" the girls said together. "Who would do something like that?"

"People with baaad parents," I said, moving them along.