I don't know about Mice or other critters but I read a book that said Rats have an enzyme in their digestive tract that can digest Rubber.

Not related but a funny story:
When I was around 13 years old my Neighbors took me on a Van camping trip around the various parks all they way from LA up north in CA.

The Father questioned me as to why I bought 6 pair of cotton boot laces with me. (I had bought them at some surplus store and they were tied together so I simply threw them all in my stuff before we went.)

The Wife and Daughter slept inside the Van and the Father and myself slept outside. On one of the nights Some critter ate the Fathers leather boot laces right up the middle of like 6 spots where the laces were still laced through the holes.

So the Father is the one that benefited from me bringing extra boot laces along.

__________________
84 300D, 82 Volvo 244Gl Diesel