The grass will be back if the damage is not severe. Seeding will be also of help I think.
Two links FYI:
http://forages.oregonstate.edu/organizations/seed/osc/brochures/water-quality/voles.html
http://www.agnr.umd.edu/MCE/publications/publication.cfm?ID=146
Two links FYI:
http://forages.oregonstate.edu/organizations/seed/osc/brochures/water-quality/voles.html
http://www.agnr.umd.edu/MCE/publications/publication.cfm?ID=146