Because they're squealers.
What happened when Sam's mum went on a crash diet?
She ended up looking a total wreck.
What happened when Simon tried Morris dancing?
He fell off the car bonnet.
What happened when the Wallies went skiing?
They refused to go out until the slopes had been gritted.
What's the most popular phrase at school?
I don't know!
Why do African elephants have big ears?
Because Noddy won't pay the ransom.