Answer:
Often held but never touched. Always wet but never rusts. Often bits but seldom bit. To use it well you must have wit.
I have a face, yet no senses. But I don't really care, because time is of the essence.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
It is a sound of empty, speak and it'll talk back plenty. But all the more you yack, you'll get the same words back.
I fly through the air on small feathered wings, seeking out life and destroying all things.
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?