Here in the Charlotte area, the rabbits aren't too fussy. Star-of-Bethlehem seems to be one of their favorites. They mow down the leaves, but seem to leave the flowers alone. The deer don't pass up Caladium (particularly in pots) and after finished with that move on to the elephant ears. They even mowed down an Autumn Fern last winter. No idea which species likes the bleeding heart, but something does.
As for voles, God help the Hosta and most everything else in their path. Best solution so far has been a friendly neighborhood cat and when it isn't around some mice bait placed in the openings of their tunnels.
For the voles in your hostas, try these possibilities:
-mice bait is in the ground for a long time; try baiting mouse snap traps with peanut butter (cover with a clay pot to keep birds and pets away)
-plant your hostas in a sea of small rocks; the voles will avoid the struggle
-plant your hostas in containers raised on bricks (to keep the voles from getting in through the bottom holes...they are persistent pests but don't climb well.)
Hope these ideas help. We have taken all our hostas out of the ground and put them in containers here in western Delaware. They are just as pretty and last a lot longer. Now if I could just figure out what to do with the roses...:-)