Did they run out?

This room is currently called "The Bat Room":

Why? Because that black trash bag on the ceiling is where the attic access is. That's how the bats were getting into the house. I hope to one day change the name of this room to a pretty color or something equally appealing. But for now, the room has to live with its stigma.

Additionally, there is another problem with this room...

It has two flavors of ceiling tiles... (you may have to click to actually see the difference)

So... Maybe they ran out of one type and switched to the other? WHY?