This thread is more than 13 years old, but I still wanna reply.
Yeah, that does make sense.
I personally think that living underground makes a lot of sense. When you live underground, you're safe from predators and larger animals can't harm you that much.
For intelligent rodents living underground, fungi would be the most likely be first on the domestication table, being able to be grown underground. I think that insects would be best for domestication. What do you exactly mean by spring tension?