Oddly enough,
Rodents of all types and forms have a need to gnaw on anything they can find, it keeps their front teeth in check.
This is why you might find the hardest of things around have been chewed on where there are rats, squirrels, etc.
I remember an old guy from Canada telling me this some years ago.
He said if a rodent isn't able to gnaw on something to wear it's teeth down, it can actually die from mal-nutrition from not being able to eat properly.
