What part in the Body makes a Vampire Bat change into a person?

the metosora this part is found near the heart. the bat can change into a human when ever it feels like. you can tell if its a vampire by its eyes(the bat) if there red its a vampire if not then its a normal bat the metosora this part is found near the heart. the bat can change into a human when ever it feels like. you can tell if its a vampire by its eyes(the bat) if there red its a vampire if not then its a normal bat