In this salmagundi of abstruse science, informative history and engaging personal anecdotes, Schutt's fascination for “sanguivores” goes a long way toward disarming, while defining, our primal fear of creatures that feed on blood. For all their fearsome rep@utation, only three of 1,100 bat species savor blood, and one of those preys exclusively on chickens. The author doesn't make sanguivores entirely cuddly: part two opens with the horrifying theory that George Washington was likely bled to death by ill-informed doctors and eager leeches, and includes an account of the first dog-to-dog transfusion in 1666 (the first successful human transfusion was in 1901). In part three, Schutt surveys other blood feeders: leeches currently making a comeback in modern medicine, pesky bedbugs and chiggers, and potentially lethal mosquitoes and ticks. One oddity (and typically fascinating tidbit) in the sanguivore world is the “vampire finch” of the Galapagos, which Schutt theorizes is evolving before scientists' eyes, turning to blood-sipping when other nourishment is in short supply. Passages that focus on the science can be a slog, but are quickly alleviated by sections that are witty and illuminating. (Oct.)