Though this is not traditional , mirrors have been used to make vampires stay away ( in some cultures , vampires do not have a reflection and sometimes do not have a shadow , perhaps as a way of showing that they do not have souls ) . Vampires are said to be unable to walk on consecrated ground , such as those of churches or temples , or cross running water . Although not traditionally regarded as an apotropaic , mirrors have been used to ward off vampires when placed , facing outwards , on a door ( in some cultures , vampires do not have a reflection and sometimes do not cast a shadow , perhaps as a manifestation of the vampire 's lack of a soul ) .