Utah State University Extension
Voles occupy a wide variety of habitats, depending on the species. Generally, voles prefer areas with heavy ground cover of grasses, grass-like plants, or litter. When two or more species inhabit an area, they generally occupy different habitats.
West, Ben C. and Messmer, Terry A., "Wildlife Damage Management Series - Voles" (2010). All Current Publications. Paper 1255.