“The Zoo and the Carnegie Science Center are my two favorite places in the world!” chirps my daughter from the back of the van. “Can we go to the Science Center instead?”

“No, honey, we’re driving to your penguin class,” I tell her.

She grabs her brother’s arm. “Both of us?” she asks.

“The two of you are in different classes,” I say.

From the back of the van, wailing. “But I want Peter!”

Like most siblings, my kids (age 10 and 6) don’t always get along. But since they’re home-schooled, they spend a lot of time together doing lessons at the kitchen table — or rolling on the ground near the kitchen table… here’s my son reading his geography book:

A few years ago, when Carolyn learned that she wouldn’t be able to marry her brother when she grew up, she decided that the next best thing would be to live with her husband on one side of a duplex, while Peter lived with his wife on the other side. Between the two houses will be a laboratory, where they can experiment with robotics and genetic engineering.

While my kids have a lot of experiences together, neither is exactly shy with other people. Lately my daughter will introduce herself to a potential playmate — such as a five-year-old boy in a fast-food play area — by blurting, “Hey!  Do you like playing with tomboyish girls?” (The boy looked completely floored, as if he was asking himself for the first time, “Well, do I?”)

As we wait in the lobby for the zoo class to start, Carolyn starts tossing her hat in the air. Soon six or eight kids have joined her, and they are making up a hat game that involves lots of running, throwing and catching, and the occasional animal noise.

Peter watches as a cheerful nine-year-old girl patiently mediates a hat-related dispute between her two little brothers.

“Now that’s the kind of person I’d like to make friends with,” Peter says to himself, and strides over to her. “Hello, do you like science?”

And I swear this is what he says next:

“Unless it would bore you, I’d like to share my ideas for fighting cancer through viral intervention therapy.”

I almost do a spit take, but as it happens, the girl says she does like science. Peter and his new friend stand close together to one side of the lobby, as the general hat-chasing scrum surges around them.  They discuss Peter’s intention to reprogram the DNA of a virus, so that when it burrows into a cancer cell it will incite the cancer cells to attack each other. They also discuss the merits of the book Coraline.  Oh, and at one point, Peter is rolling on the floor, re-creating an America’s Funniest Home Videos clip in which a football smacks a kid in the butt. (Well, he is ten.)

Peter was a penguin encyclopedia when he attended his first penguin class about four years ago, though he was a little skittish when it came to meeting Sukey, a frisky two-year old Penguin.  Today is Carolyn’s first penguin class, and she’s not skittish at all — in fact, she’s the first in line to touch Mickey.

A zoo employee tells us about how emperor penguins care for their young.  My daughter is initially horrified to learn that emperor penguin chicks don’t grow up with any brothers or sisters — the parents have only one egg at a time.

“During the middle of the winter, while the mother penguin goes off looking for food, the father penguin stays with the egg. He doesn’t go anywhere for six weeks,” says the teacher. “Penguins are great parents.”

My daughter brightens.”My daddy is like a penguin!”

An appreciative “Awwww!” rises from the adults in the room. One mother near me mutters under her breath, “The same can’t be said of every father.”

“Did I embarrass you, Daddy?” my daughter shouts, delighted. “Daddy the penguin! Daddy the penguin!”