The Stud Finder

The other day Dad was playing around with my grandfather's stud finder. Dad was doing something with the walls in his classroom, and needed to find said studs in said walls. When he was finished with it, however, he put it on the counter to be returned to my grandfather. This morning I found it and, being interested in what exactly it did, I picked it up and began fiddling around with it.
I asked Robert what a stud finder was.
Robert, nonchalantly leaning against the counter: "Well, usually it's something that girls carry around when there are guys around."
Me, rolling my eyes after thinking for a moment: " ..... ha ha ha. That's a scream, Robert. Literally."
Now, for those of you who don't know what a stud finder is, it looks somewhat like a really thick remote control. You squeeze the sides to turn it on. It has five tiny lightbulbs in a vertical row, and as you pass it along a wall, the lightbulbs light up to indicate how close you are. When you've located a stud, the top lightbulb lights up and a high pitched beep holds out through the air.
As I was playing around with it, passing it along the wall in the kitchen, I got to the corner, which leads into the dinning room, and was about to put it back on the counter, when George walked around the corner right into the stud finder. Both he and I were so surprised to find someone right there, that he stopped about an inch away from the stud finder, and I forgot to stop squeezing it.
The top light lit up. The beep sounded. I stared at it. Robert burst into gales of laughter. And George rushed at him and began "beating him up". Robert was still laughing, and trying to hold him off, and then George started laughing too. I still couldn't believe what had just happened. I set the stud finder down on the counter with a dazed look on my face.

So, now I kinda thinking Robert was right. I should totally carry a stud finder around with me. ;)