http://www.wired.com/news/furthermore

Dracula's Dream
02:00 AM May. 18, 2004 PT An elderly couple in Davenport, Iowa, awoke to a surprise on May 11: Blood was splattered all over the floor and along several walls in their house. Investigators first thought an animal had sneaked into the house, but the blood turned out to be human. Elmer and Viola Stacy, both in their 90s, were not injured, and said they locked the door before they went to bed. Sheriff Mike Brown said except for the blood, "nothing was amiss and nothing was knocked over." The mystery was solved Monday, however, when tests revealed the blood came from Viola Stacy, who apparently had an arterial hemorrhage on her lower leg. Brown said she didn't realize she was bleeding, but the pinhole-size wound still spurted blood voluminously -- until it stopped as quickly as it started, leaving no bloodstains near her bed.
-- Debra Jones

(Thanks to FredA!)