...two vampire bats are hanging in a cave. One says "I feel like some blood, and I want it now!"
The other says "There's nothing around for miles. Go back to sleep."
But the first bat flies off coming back a few minutes later its face covered in blood.
"Where'd you get that?" asked the second bat.
The first bat finished licking the blood off, and said "Do you see that tree just outside the cave?"
"Yes" said the second.
The first said "Well I didn't"...
