I've set Finder preferences on my MacBook Air running OS X 10.9.1 to show everything on my desktop:
I've noticed that storage partitions called Recovery HD and EFI appear there:
What are they? Is there a setting I can use to hide them?
I've noticed I can eject them, but they will reappear later, such as when I wake my MacBook Air after sleeping.
Update: I'm using Mountain (which I recommend), and it turns out either the "Mount all unmounted volumes on wake from sleep" setting was on by default, or I didn't remember setting it.
Since I turned it off those partitions have stopped mounting automatically.