Answer:
My teeth are sharp, my back is straight, to cut things up it is my fate.
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
Break it and it is better, immediately set and harder to break again
Take one out and scratch my head I am now black but once was red.
A harvest sown and reaped on the same day In an unplowed field, Which increases without growing, Remains whole though it is eaten Within and without, Is useless and yet The staple of nations.
What never gets any wetter no matter how hard it rains?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?