Knock knock.

Who's there?

Banana.

Banana who?

Banana honk honk!

(Repeat, then repeat again and again and again.)

The first time my 4-year-old told me that joke, I laughed at the absurdity of it.

The 10,000th time I laughed because that's what you're supposed to do when your kid tells you a joke, even when you've heard it before and, yes, even when it doesn't make sense.

The good thing about preschool humor is that preschoolers tend to crack up at their own jokes and they usually have infectious laughter.

It's when they pause for a response that things get tricky.

You're left with few choices. A hearty laugh will encourage them to keep telling the same joke over and over, and generally louder as they get excited. A half-hearted chuckle could discourage them from trying to find a joke that's actually funny.

Not laughing at all? Why would you do that?

My daughter has only recently started telling jokes, and ever since her successful foray into knock-knock jokes, she's telling them nonstop.

However, she hasn't managed to come up with a single play on words. In fact, she doesn't understand the humor in it. While I laugh every time she tells me a joke, she just looked at me quizzically when I told the old, "Olive you!" knock-knock joke.

When my 11-year-old tried to interrupt her with an "Orange you glad I didn't say banana?," his sister was more puzzled than amused.

She obviously doesn't believe in laughing at other people's jokes just to be polite.

While "banana honk honk" has been a favorite for weeks now, my daughter has now decided to incorporate physical humor into her knock-knock routine.

The other night, she snuck up on me wearing a chicken costume — but that wasn't meant to be the funny part.

The joke went like this:

"Knock knock."

"Who's there?"

"It's Sloanie!" she announced, peeling away her chicken hood.

"Knock knock," she said again. "Mom, you have to see who's at the door!"

"Who's there?"

She pulled the hood back up and said, "It's a chicken."

Then she immediately pulled it back down and said reassuringly, "I'm just joking, Mommy. It's really Sloanie."

That shtick lasted until the costume got too hot to wear.

I have to admit that her knock-knock jokes are fun, even if they aren't punny.

A blogger at http://blogs.honoluluadvertiser.com, Treena Shapiro hunts for child-rearing tips, family-friendly activities and amusing anecdotes. She'll share the best and the worst here.

Reach Treena Shapiro at tshapiro@honoluluadvertiser.com.

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