Answer:
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
I am always hungry, I must always be fed. The finger I lick will soon turn red.
I have it, I don’t share it. If I share it, I don’t have it. What is it?
The man who invented it doesn't want it. The man who bought it doesn't need it. The man who needs it doesn't know it. What is it?
I have five letters and people eat me. When you remove my first letter I become a crime. Remove my first two letters and I am an animal. If you remove my first and last letters I'm a form of music
I am owned by Old McDonald.
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?