Sims will always allow vampires to bite them. Only family members can be vampires by bite. Vampire’s won’t wear their special skins and outfits. If a vampire bites a normal sim, that vampire’s hunger motive will be rising. Originally there is a limit so only 10 or so townies can be vampires. 1.) A Collection of Six Vampire Hacks – Up to 100 townies can be vampires.
