Because they always leave you stumped!
Because they always want to be right.
They didn't know you could get Britain to leave by voting.
What has a foot but no legs?
Sir. Groan worthy penguin jokes(https://allwrong.wordpress.com/2007/10/05/penguin-riddles/)
Elephant snot. Funniest part is seeing people's reaction when you tell it.
It died.
It was stumped.