Answer:
Some are clean and some are dirty, but all are meant to get a chuckle. Most like it, some takes offense from it.
What do elves do after school?
It is everything to someone, and nothing to everyone else. What is it?
Why did the monkey fall out of the tree?
What's funny about 3 helium atoms?
I am carried by mad animals.
Funny
Animal
Difficult
Easy
Food
Kids
Logic
What am I?