Good Riddles

 
Why Did (medium)

Question: Why did the boy throw the butter out the window?

Question: 8,549,176,320 What makes this number unique?

Riddle #525 (medium)

Question: In Michigan you cannot take a picture of a man in a green hat.

Why?

Question: What goes up but never comes down?

Riddle #456 (medium)

Question: I am a big threat to humanity,
but you wouldn't get rid of me even if you could.

What am I?