However, home ranges shared by two females have been observed. Breeding males range over larger areas occupied by a number of females. Litters of 4-7 young are born in successive pregnancies from March to October but autumn litters are small. Growth in the summer is rapid and females can become pregnant when they have reached a weight of 12 grams. Breeding may continue over the winter if a good food supply, such as a heavy acorn crop, is available.
Few adults survive from one summer to the next.
Their predators include foxes, weasels, owls and domestic cats. Wood mice are important prey items for tawny owls and when numbers of woodland rodents are low owl breeding may not take place. Wood mice can become pests of stored food in buildings and will take bulbs, beans, peas and tomatoes from the garden. Generally they seldom cause economic damage. Minor losses to forestry and agriculture due to wood mouse feeding can be ignored when balanced against the consumption of weed seeds and invertebrate pests.