Q: Why can't penguins fly?
A: Because they're biscuits.
Chloe, Charlotte and Imogen, 13, from England

Q: Why did the boy throw the butter out of the window?
A: To see the butterfly
Raheela, 13, from England

Q: What's the difference between Alex Ferguson and Elvis?
A: Alex Ferguson still plays Giggs
Ronan, 10, from the Republic of Ireland

Knock knock
Who's there?
Little man
Little man who?
Little man who can't reach the door bell!
Chloe and Imogen, 13, from England

A man walks in to the doctors and he says to the doctor "doctor, I keep getting bad stomach cramps." 
The doctor says "well what have you been eating?"
The man says "snooker balls."
The doctor says "which ones?"
The man says "the red ones, the pink ones, the blues ones and the black and white ones." 
The doctor says "well it's clear that the problem is you haven't been eating enough greens."
Megan, 12, from England

Knock knock
who's there?
Bear
Bear who?
Bear bum
Gwen, 15, from Scotland

Q: What did the pen say to the other pen?
A: You're looking sharp today
Shannon, 11, from Ashington in England

Knock knock
Who's there?
Doctor
Doctor who?
You just said it
Sophie, 8, from England

Q: Why did Mozart get rid of all his chickens?
A: They kept saying 'Bach! Bach! Bach!'
Zenon, 15, from Wales

Knock knock
Who's there?
The interrupting sheep
Tthe interupting sheep who?
The interrupting sheep..... BAAAAAAAAAA!!!!
Ross, 9, from England

Q: What do you get if you cross a cow and an earthquake?
A: A milkshake
Prerna, 9, from Asia

Q: How does Good King Wenceslas like his pizza?
A: Deep and crisp and even
Ben, 8, from England

Knock knock
Who's there?
Andrew
Andrew who?
Andrew on the wall
Miltyanna, 10, from England