face prints

I have 2 closets in my bedroom. My bedroom was originally the master bedroom, but then my parents decided to switch bedrooms with me so they could do some adding on...so now I have the "master bedroom"...sorta. Anyway, the two closets have 2 sliding glass mirror doors...each. So a total of 4 huge mirror doors. I clean them every once and a while, definately not as often as my mom tells me to do, but c'mon, I'm a busy college student who doesn't really care about smudge marks on the mirrors. The real reason why I can't stand to clean them is because of this:

Every time I clean those blasted mirrors...a few days later, there appears a "face print" right on the center of the mirror. For those who don't know what a "face print" is, it's when someone presses their oily little face on glass, or in my case...a mirror. It leaves a distinct print of their nose, mouth, chin and sometimes, their forehead. Their eyes are also accentuated by the silhouette of the eye cavity. When the print is left on the mirror, it looks both frightening and humorous; only someone who has seen a "face print" can fully understand what I mean by this. They look ghoulish, and also playful at the same time. "Face prints" most commonly show up in these places:

1. my mirrors
2. our home windows
3. our car windows

Anyway, back to my story...I find these "face prints" all the time. Who is this "face print" bandit?! He seems to be about 5 feet tall...with a cute button nose. I have a certain family member that fits that description, and his name starts with a "Z" and ends with an "ach"...