Knock Knock

We have recently found ourselves deep in Knock Knock mania. Luckily this has coincided with bodily part/bodily function fascination so really great jokes go something like this:

Knock Knock.
Who's There?
Boo.
Boo Who?
Booby.

Wild laughter.
Or this favorite:

Knock Knock.
Who's There?
Poo.
Poo Who?
Poopy.

Side grabbing, knee slapping laughter, uncontrollable giggling, clear indicators of future comic genuis, these are gems. I try to incorporate some non body part wittiness at the four year old level:

Knock Knock.
Who's There?
Tank.
Tank Who?
You're Welcome.

They laugh, a small smile for my consideration and hard work and then they are right back in it, creating zanies all on their own. Consider all the possibilities: who's there? Toe, toenail. Or boog, booger. Just so witty, so on. In a family that really values the sense of humor, well we couldn't be more proud of these children. Where do they get this stuff?