In reply to Sl@te Head:
Almost got knocked off balance by a dormouse that jumped from a hole and ran down the rock right next to my face on the Kleine Herkulessäule in Saxony. No idea who was more startled!
However, the most likely cause of death by rodent is of course Hantavirus associated kidney disease (transmitted via mouse droppings, especially in bivy huts in Scandinavia), or for extra style point plague (transmitted by chipmunks and their ilk in Colorado and Arizona).
Squirrels in the UK can actually carry leprosy, so better watch out!
CB