Here's a vampire Bat Joke:
Two vampire bats are sitting in cave: The first bat says "I'm dying for some blood, I'm going out to get some". So off he flies out of the cave. About 15 minutes later he comes back with loads of blood dripping from his mouth. The other bat starts drooling and asks "Where'd you get the blood ?". The first bat says "Come with me and I'll show you". So off they fly out of the cave. After a few minutes they are flying over a large cemetery, when the first bat says "See that great oak tree over there? I didn't!"