Voles are small rodents that are relatives of mice, but with a stouter body; a shorter, hairy tail; a slightly rounder head; smaller ears and eyes; and differently formed molars (high-crowned with angular cusps instead of low-crowned with rounded cusps). They are sometimes known as meadow mice or field mice in North America and Australia.
Vole species form the subfamily Arvicolinae with the lemmings and the muskrats. There are approximately 155 different vole species.
They are small rodents that grow to 3–9 in (7.6–22.9 cm), depending on the species. Females can have five to 10 litters per year. Gestation lasts for three weeks and the young voles reach sexual maturity in a month. As a result of this biological exponential growth, vole populations can grow very large within a very short time. Since litters average five to 10 young, a mating pair can birth a hundred more voles in a year.
Voles thrive on small plants yet, like shrews, they will eat dead animals and, like mice or rats, they can live on almost any nut or fruit. In addition, voles target plants more than most other small animals, making their presence evident. Voles readily girdle small trees and ground cover much like a porcupine. This girdling can easily kill young plants and is not healthy for trees or other shrubs.