Short easy simple riddles for teens

I live in the ocean. I swim wherever I want. I sing to my family. I can breathe through a hole in the top of my head. I am a...

I live in a house. Each Halloween I stand in a jack-o-lantern and get shorter as I grow old. What Am I?

What kind of cup doesn't hold water?

You always carry me in your hand, always with you, from your birth till your death! I am a fruit. What Am I?

What comes down but never goes up?

I always come down and never ever go up? Think, think and think! We all just love it.

I know a word which reads the same when written forward, backward or upside down. Do you?