Disappearing Act

My roommate, QiQi, does a disappearing act about three to four times a week.

Either I'll come home and find that there is pasta mid-cooking on the stove (the burner will be off, though)... or, more recently, her gallon of milk will be sitting out on the counter...

I'll wander around the house and find that she's nowhere...

Sometimes, I'll be in my room with my door open (because otherwise I get absolutely NO heat), and she'll have been around doing stuff and then all of a sudden its like she vanished without a sound. I'll get up and look around and she's just gone.

When she first moved here, I was very intentional about saying goodbye when I left... and she did it, too. And I guess I understand why I like that, now... because to have someone just disappear is very jarring, even if you know there isn't any reason to be alarmed because it happens so often... its just... weird, right?