Why did the ---- cross the road?

I love driving in the car with the kids and listening to hours of them asking "Why did the ----- cross the road?" Then they make up a random answer that has nothing to do with the question (at least the younger two) and I have to pretend that I "get it". Laura always starts off with, "Mommy, I have a question."
"Ok, Laura, what is your question?"
"Why did the monster cross the road?"
"I don't know, why"
"Because he wanted to go to the other slide. Get it, slide."
This activity could entertain them for hours, except that it drives me crazy after about 15 minutes.

Another fun game we play while driving is a version of 20 Questions in which the answer is always an animal. Joshua likes to come up with the most obscure animal imaginable. The game goes like this when Benjamin is thinking of an animal,
Daddy: Is it a mammal?
Benjamin: I don't know.
Daddy: Does it live in the water?
Benjamin: I am not sure.
Daddy: Does it have 4 legs?
Benjamin: I forgot.
Needless to say, we don't often guess the animals that the kids are thinking of.

Laura wants to know when she can go trick-or-treating again. Every time we've gone to a program at the library since Halloween she hopes to go trick-or-treating again or to get more candy (we went to a storytime that involved trick-or-treating in the library on Oct 30).