He had spotted them on the last trip to the hardware store and begged dad to buy some, but Bon Adventure had found the right type of shovel he required, so he wanted to pay for it and go home. The package David held up contained a dozen circular cakes designed to dissolve in water.
“But look what it says. We can put them in the water out in that ditch, and then they will kill all the mosquitoes.”
Bon Adventure took the package and read the list of ingredients.
“Those are pretty expensive, son, so I’m not sure we can afford it right now. Why don’t you put them back, and we might get some later, okay?”
That satisfied the boy at the time. But after school today he went out behind the house and slipped through the gap in the chain link fence that separates the tree line from the ditch so he could go adventuring. He then comes to the deck with a small gourd he had discovered, two muddy feet and several new mosquito bites.
“Dad, you can have this one to add to your collection. Can we go to Ace now?”
David scratches both legs while Bon Adventure takes the little gourd and examines it. He wipes away some dirt before he lays it on the table beside his chair.
“You know what I heard today, son? You will like this story.”
David picks up the gourd, and then holds it upside down.
“Look, it’s an alien head.”
“Very funny. Did you hear what I asked you?”
The boy makes a show of putting the gourd exactly back where he got it, and then gives his dad a serious face.
“Okay. Today I discovered that if you put a small amount of soap in water, guess what happens to the mosquitoes?”
“They get clean?”
“No, silly. Think about what soap does to water.”
“What are you talking about, dad? It would be like giving them a bath, I guess.”
He eyes the gourd again.
“Oh, so you don’t know about surface tension?”
David tilts his head back as he curls his lip into a snarl, saying in effect,
“If you take a bead of water that is, let’s say, sitting still on a countertop, and then you add a tiny bit of soap to it, the water bead will collapse.”
His flattened hands spread apart through the air to demonstrate the effect.
“The soap breaks the water tension.”
“Oh! I get it now!”
“Then what would happen if you add a drop of soap in a cup of water, and then a mosquito landed on it?”
His eyes lit up suddenly.
“He would drown?”
“She would drown. The males don‘t lay eggs.”
“Cool! Well forget the cakes, dad -- can I just have some soap?”