Answer:
I am needed for most animals and hardcover books. What am I?
I may be made of metal bone or wood and have many teeth. My bite hurts no one and the ladies love me.
The more holes you cover the lower I go.
When it comes to me you go on red and stop on green.
Only one color, but not one size, stuck at the bottom, yet easily flies. Present in sun, but not in rain, doing no harm, and feeling no pain. What am I?
What never gets any wetter no matter how hard it rains?