They Disapparate and turn into Vampires.

They can disapparate (wizards of age can just transport themselves by vanishing from one place and reappearing at another)

J.K. Rowling also mentions that the house elf magic is totally different which allows them to apparate and disapparate inside Hogwarts.

Disapparating is when you teleport magically. Say like I disapperate from London them apperate in Hogs-Mead. (Apperate means to appear magically.) J.K. Rowling created the term for the special usage in Harry Potter.

well Harry Potter has the advantage of the expelliarmus spell...but Darth vadar has a light saber (doesn't a light saber make whatever it touches disappear or something?)

i guess if harry was scared he could just disapparate.