Wood mouse facts
Length
8–11 cm, plus a 7–11 cm tail
Weight
13–27 g
Lifespan
About a year on average
Diet
Seeds, nuts, fruit, buds, fungi and insects
Young born
March to October, litters of 4–7
Status
Native; Least Concern in Great Britain
How to recognise a wood mouse
The back is sandy or reddish-brown and the belly is pale, often white, with big ears, large dark eyes and a long tail. A house mouse is smaller and greyer, with no clear line between back and belly, and much smaller ears. A yellow-necked mouse is a little bigger, with a complete yellow collar; a wood mouse has only a small yellowish streak on its chest. Bank voles have smaller eyes and ears and a shorter tail.
Where do wood mice live?
Throughout the British Isles, even on small islands. They live in woodland, hedgerows, grassland, farmland, parks and gardens, avoiding only very wet or bare, exposed ground. They nest in burrows, tree holes and sometimes buildings or nest boxes.
What do wood mice eat?
Their diet changes with the seasons: acorns and ash and sycamore seeds in winter, buds in spring, caterpillars and worms in early summer, and blackberries and fungi in autumn. They store spare food in their burrows.
When do wood mice have babies?
Litters of 4 to 7 young are born from March to October, and in years with plenty of seeds, wood mice may breed right through the winter. The young stay with their mother for about three weeks.
Signs to look for
- Nibbled hazelnuts: a neat round hole with tooth marks on the inner rim and on the shell around it. Voles leave marks only on the inner rim, and squirrels split the shell in half.
- Food stores: piles of shells and seed husks in old bird nests, on tree stumps or between roots
- Pips: fruit with only the pips eaten out
Its link to the badger
Wood mice are a small but important part of the night-time food web. Badgers use their sense of smell and strong claws to dig into small mammals' burrows and nests, and wood mice are also key prey for tawny owls and barn owls.
How you can help
- Leave hedges, log piles and leaf litter in your garden for cover and food.
- Let some plants go to seed in autumn.
- Avoid rat and mouse poison outdoors, because it harms the owls and other animals that eat mice.
- To watch wood mice, sit quietly at dusk near fallen fruit and nuts with thick cover nearby.