Vampires are said to be humans who once cheated death by drinking the blood of others and must therefore continue to drink the blood of the living in order to remain immortal. Consequently, they are believed to have become creatures with supernatural powers, such as amazing strength and the ability to hypnotize potential victims. In some fictionalized accounts of vampires, these creatures can also fly, sometimes after turning into a bat. There has been no physical evidence that such creatures are real, and indeed most people believe that vampires are figments of the imagination whose characteristics are largely based on the vampire in the novel Dracula by Bram Stoker. Some, however, insist that vampires are real creatures, who hunt alone or in bands that roam the streets of large cities looking for lone victims who will not be missed. These creatures, believers say, die when exposed to sunlight, cannot enter churches, and have an aversion to religious symbols such as crosses and to holy water. In addition, they are said to be repelled by garlic. (Some say that these things can kill a vampire, but others believe they only drive away a vampire.)