According to the myths and movies vampires cast no reflection in mirrors because they have no soul, making it easy to identify any bloodsuckers hanging around your house.
But this part of the vampire myth has always made me wonder- do vampires see a reflection when they look in the mirror, or do they see an empty frame like normal humans do?
That sucks for them if they can't see their reflection in the mirror because, as this Random Crab comic shows, vampires are hardcore pranksters so mirrors probably factor into a lot of their pranks.
Maybe that's why so many vampires carry parrots around on their shoulders...
-Via Geeks Are Sexy