Wood mice are generally nocturnal, but males, or females suckling young may be active for short times during the day (4). They feed on seeds, invertebrates, fruits, nuts, seedlings, moss and fungi (4), and food is often stored within tunnel systems (3). All mice engage in 'refection' in order to fully digest food; they eat soft faeces that have already passed through their digestive system once, allowing carbohydrates to be fully digested the second time around (3).
Breeding occurs from March/ April until October, and peaks in July and August (4). In summer, females defend breeding ranges against other females (4). Dominant males may be aggressive, and have been reported to chase and even kill juveniles (3). Before mating, males are known to produce a string of ultrasounds, which may serve to pacify the female (3). Gestation takes 25 or 26 days (3), and the litter, which consists of two to nine young (4), is born at night within the nest (3). Nests are made in underground tunnels, inside hollow logs, bird or dormice nesting boxes or in dense vegetation (3). Between four and seven litters are produced each year (4), and females are able to conceive whilst still suckling the previous litter (3). The young are fully weaned after about 18 days, and usually start to breed the year after their birth, but if they were born early in the year they may breed during the year of birth (4).
Wood mice do not hibernate, but during winter males and females may group together when sleeping for extra warmth (3). The maximum life-span is 18 to 20 months. This species has many predators, including foxes, weasels, cats, owls and kestrels (4); the wood mouse has evolved a number of strategies to avoid these predators, it can make impressive leaps to safety, and can shed the skin of the tail if it is gripped anywhere other than its base, allowing the mouse to escape. The skin does not grow back; instead the area of the tail dies and falls off (3).