Answer:
I am Invisible Man's drink at snack time
Light hides me and darkness kills me. What am I?
It's been around for millions of years but is never more than a month old. What is it?
I row quickly with four oars, but never come out from under my own roof. What am I?
What can you lose that will cause other people to lose theirs too?
No matter how little or how much you use me, you change me every month.