Answer:
If I have it I don't share it. If I share it I don't have it. What is it?
I am an insect half of my name is another insect. I am similar to the name of a famous band.
So simple, that I can only point. Yet I guide men all over the world.
I am long and slim works in light. Has but one eye and an awful bite.
A sport with love and service played by singles and pairs.
No matter how little or how much you use me, you change me every month.