Three bats are having a contest to see who can suck the most blood.

The first one leaves and comes back half an hour later with his mouth full of blood; "See that bell tower? I went over there and sucked the blood of everyone in the church!"

The second one leaves and comes back an hour later with his face covered in blood; "See that bell tower? I went over there and sucked the blood of everyone in the village!"

The third one leaves and after two hours comes back completely drenched in blood from head to f… to his feet—err, paws; "See that bell tower? Well, I didn't see it."