Two Vampire bats are in a cave, both very hungry. The first bat goes out looking for some food. He comes back later with nothing.
The second bat tries not long afterwords. 5 minutes later he returns, blood all over his face!
“Wow!” said the first bat “You must’ve had a big meal, where did you get that?”
“Well, can you see that large redwood over there?”
“Yes” replies the first bat.
“Well I bloody well didn’t.”