*engage Arnold Rimmer mode* it's aliens
Lister: Your explanation for anything slightly peculiar is aliens, isn't it? You lose your keys, it's aliens. A picture falls off the wall, it's aliens. That time we used up a whole bog roll in a day, you thought that was aliens as well.
Rimmer: Well we didn't use it all, Lister. Who did?
Lister: Rimmer, ALIENS used our bog roll?
Rimmer: Just cause they're aliens doesn't mean to say they don't have to visit the little boys' room. Only they probably do something weird and alien-esque, like it comes out of the top of their heads or something.
Lister: Well I wouldn't like to be stuck behind one in a cinema.