Terry Pratchett 
Carpe Jugulum 
(Discworld Novel 23)

”’ Carpe Jugulum, ” read Agnes aloud. ” That”s . . . well, Carpe Diem is Seize the Day, so this means -”
” Go for the throat . . .”’
Vampires have come to Lancre, but they”re not what you”d expect. Sure, they drink blood and view humans as dinner, but they”re modern and sophisticated. They”ve got style and fancy waistcoats. And they”re not a bit afraid of garlic.
The Magpyr family are out of the casket and want a bite of the future. But they haven”t met the neighbours yet.
Between them and Lancre stand a coven of four – Granny Weatherwax, Nanny Ogg, Magrat and young Agnes – and they don”t take kindly to murderous intruders . . .
”An enduring, endearing presence in comic literature” Guardian
”Incredibly funny . . . compulsively readable” The Times
Carpe Jugulum is the sixth book in the Witches series, but you can read the Discworld novels in any order.