Oh (a story about the educational system and one thing that might possibly be wrong with it).

WHAT ARE YOU DOING??!!
I shrieked at him in a hybrid scalding-scolding tone.
Why are you trying to crush that poor little ant?!

Daddy, I was -

I interrupted.
Listen, that little ant is not in our home. It's close to its own home. It's not hurting us, or invading our house, or eating our food. Why are you trying to smash it?

Well Daddy, I was -

I interrupted, out of necessity, because my lesson was not getting through.
Do you remember what hard workers ants are? They are valuable members of our ecosystem and we can learn a lot from them. This little guy here was probably heading home trying to get to his family when you, a big mean giant, almost killed him.

We watched the little fellow skimp along. I felt my son take a breath to try defending himself again, so I moved quickly to block it.

Listen buddy,
I said, not totally unkindly, with just the right mix of educational moment condescension.
We've gotta look out for people and creatures smaller than us, okay? When they're not bothering us, why should we go bothering them?

Okay.
he said.
But I was -

Just please listen.
I said.
Just listen, because this is important. It may be a little ant, but it's not a very kind thing to do to go killing creatures, no matter how small, just for fun, or because they're simply in front of you. Haven't we read enough Dr. Seuss and Far Side for you to know this?

Yeah.
he said.
I wasn't actually trying to kill it. It was walking toward a stream of water and I thought it might drown so I was putting my finger next to it to help it go away from the water so it wouldn't drown.

Oh.
I said.
Oh.

Oh.

Uh-oh.