Answer:
A hole leading in, a hole leading out, we connect to a cavern that is slimy all throughout. What are we?
What turns from red to black as soon as it touches water?
I cannot be felt, seen or touched. Yet I can be found in everybody. My existence is always in debate. Yet I have my own style of music.
What goes through a door but never goes in. And never comes out?
The higher I climb, the hotter I engage. I cannot escape from my crystal cage.
What is lighter than what it is made of?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?