Do agnostics feel that all deities have to be disproven in order to be atheist?

To be honest i really never understood agnostics. They believe you can not know for sure if god does or doesn't exist, why don't they apply this to everything in their life? Are you agnostic towards santa clause and the easter bunny as well? Obviously no one can know with 100% certainty whether or not any deities exist, but you don't need to. To our everyday knowledge, there hasn't been any empirical evidence for god, and therefore we shouldn't believe that there is one. For the rest if the things we don't know, we can say, we do not know! You don't need to know the whole universe 100% in order to know that santa claus isn't real, because if you do, well, you know.