I've been reading Dark Banquet- Blood and the Curious Lives of Blood-Feeding Creatures by Bill Schutt. In a lot of ways it's kind of a spiritual successor to Carl Zimmer's excellent Parasite Rex and it's certainly worth a look. I've only just completed the section on vampire bats and begun the section on blood itself, but the book has already been absolutely fascinating. For example, of the three species of vampire bats, desmodus rotundus (the common vampire) is especially well-equipped for locomoting on the ground*. Desmodus often hunts ground-based prey, unlike its cousins that do a lot of arboreal hunting, and as such it has evolved a stronger set of hind leg bones than most bats. Thus, rather than the normal shambling gait shared by the majority of bats, desmodus can tool around on the ground by way of a speedy ape-run.
Pretty cool, huh?
*Another type of vampire, diaemus youngi, can also move around on the ground fairly well too, but desmodus is better at it and can also effect tremendous (for its size) jumps. The third species of vampire, diphylla ecaudata, has wussy little hind leg bones that aren't useful for moving on the ground. Fortunately for diphylla, it has other adaptations that make it very good at climbing trees.