Keeping with Halloween

Can you tell me why in the Pampas, ay and elsewhere, there are bats that come out at night and open the veins of cattle and horses and suck dry their veins, how in some islands of the Western seas there are bats which hang on the trees all day, and those who have seen describe as like giant nuts or pods, and that when the sailors sleep on the deck, because that it is hot, flit down on them and then, and then in the morning are found dead men, white as even Miss Lucy was?"

"Good God, Professor!" I said, starting up. "Do you mean to tell me
that Lucy was bitten by such a bat, and that such a thing is here in
London in the nineteenth century?"

From Bram Stoker's Dracula