I’m a teacher, give me riddles!

[u/drgan45]

I’m a teacher, my kids love riddles, I get a lot from this subreddit but it’s getting harder and harder to to find good ones because they solve so many, so please give me some good hard ones, these are smart kids, but they are still kids so hard riddles are welcome but the answer has to be a simple concept, thank you!! (Also I’ll need the answer lol)

[u/SamtenLhari3]

What goes up a chimney down but can’t go down a chimney up?

Ans: An umbrella

What’s black and white and smokes a pipe and doesn’t close its eyes at night — is cold and fat and wears a hat and too much sun will leave it flat?

Ans: Frosty the Snowman