Answer:
Often held but never touched. Always wet but never rusts. Often bits but seldom bit. To use it well you must have wit.
It can cause deflation of tires when dropped from the rear of spy cars.
Pregnant every time you see her, yet she never will give birth.
I sleep by day, I fly by night. I have no feathers to aid my flight.
What has one eye but cannot see?
People take me on walks and I run and have fun. What am I?