Small rodents
Source: gov.uk (2025-10-30)

Small rodents include field vole (Microtus agrestris), bank vole (Myodes glareolus), edible dormouse (Glis glis), wood mouse (Apodemus sylvaticus) and yellow-necked mouse (Apodemus flavicollis). Learn more about their impact on trees.

Area and status

Area

The non-native edible dormouse comes from continental Europe and was first introduced to the UK in 1902 at Tring Park in Hertfordshire. Today, the species live mainly in the Chiltern Hills and adjacent woodlands, staying around 35km of Tring Park itself. The Mammal Society estimated there were about 23,000 edible dormice in the UK in 2018.

Field voles, bank voles, wood mice and yellow-necked mice are all native to the UK. Field voles, bank voles, and wood mice live across most of England, Scotland, and Wales. Wood mice are also found in Northern Ireland. Yellow-necked mice mainly live in Midlands, southern England, and Wales, as shown by their records on the National Biodiversity Network (https://species.nbnatlas.org/species/NHMSYS0000080209).

Status

Management of edible dormice by use of traps requires a class license from Natural England (https://www.gov.uk/government/publications/edible-dormice-licence-to-trap-them/edible-dormice-licence-to-trap-them-cl02). Control of any of these species of small rodents must not contravene animal welfare legislation.

Associated treescape(s)

The section shows the types of treescapes where this mammal is typically found, along with the level of presence in different treescapes.

Field vole:
- lowland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (frequently found)
- mixed plantation (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-conifer) (only occasionally)
Bank vole:
- upland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (common)
- lowland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (common)
- mixed plantation and tree nurseries (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-conifer) (frequently found)
- wood pasture, parkland, and orchards (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (only occasionally)
Edible dormouse:
- lowland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (most common)
- mixed plantation and tree nurseries (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-conifer) (frequently found)
- wood pasture, parkland, and orchards (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (only occasionally)
Wood mouse:
- upland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (frequently found)
- lowland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (most common)
- mixed plantation and tree nurseries (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-conifer) (frequently found)
- wood pasture, parkland, and orchards (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (frequently found)
Yellow-necked mouse:
- lowland broadleaved woodland (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (most common)
- mixed plantation and tree nurseries (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-conifer) (only occasionally)
- wood pasture, parkland, and orchards (https://woodlandwildlifetoolkit.sylva.org.uk/advice-types-broadleaf) (only occasionally)
Ecosystem services and impacts on biodiversity

Small rodents are scatter–hoarders and help disperse seeds for broadleaved tree species such as oak and hazel. Forestry Commission guidance (https://www.gov.uk/government/publications/using-natural-colonisation-for-the-creation-of-new-woodland) highlights that wood mice and voles can disperse seeds such as beech, cherry and hornbeam up to 10 metres, which may help support the colonisation of new woodland.

While seeds are an important food source for these species, natural germination rates are typically unaffected, as many cached seeds are never retrieved.

Where direct sowing is used and seeds are densely planted together, seed predation can be very high, sometimes reaching 100%. This can limit the success of planting schemes.

Juniper seeds are highly palatable to wood mice, to the extent that direct sowing without protection is unlikely to be successful. Yellow-necked mice and bank voles both consume fir seeds (family: Pinaceae).

Small rodents serve as important prey for native carnivorous mammals and birds of prey. Voles show distinct population cycles with peaks and troughs, which can have big impacts on the populations of their predators and by consequence, other prey species such as ground nesting birds.

Identification and assessment of damage and risk to trees

The impact of small rodents on trees and treescapes varies depending on their habitat preferences and levels of specialisation. For example, field voles are typically found in open habitats and young woodlands, making them more likely to damage newly planted trees. In contrast, bank voles prefer woodlands with dense understorey cover, and their impact is more likely to be on preventing natural regeneration.

Types of damage:
- bark stripping and gnawing, which can fell saplings and kill trees
- may also browse on buds and stems
Field and bank voles:
- field voles can damage below 20cm height (rarely climb)
- bank voles can damage up to 10m height (though rare in UK)
- damage risk varies with population cycles
- bark stripping is most severe in winter
Edible dormice:
- strip bark in early summer, typically in crowns of pole-stage or mature trees
- cause stem breakage and forking
- leave distinctive rectangular stripped patches
- prefer larch, Scots pine, Norway spruce, beech, birch and orchard trees
Gnawing by these species may leave 1mm wide incisor marks, which can be distinguished from the 3–4mm wide incisor marks left by rabbits.

Managing small rodents in the landscape

Widespread use

Poisoning or trapping (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-mammals-in-the-landscape#lethal-control) (lethal control).

Occasional use

Enhance natural predation:
- nest (or den) boxes (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-mammals-in-the-landscape#nest)
- raptor perches (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-mammals-in-the-landscape#raptor)
Any control must be conducted in line with animal welfare legislation such as the Wild Mammals (Protection) Act 1996 and the Animal Welfare Act 2006.

Modifying small rodent access to trees

Widespread use

Physical exclusion from an individual tree or shoot: tree shelters, spirals, guards, and tubes (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/modifying-mammal-access-to-trees#tree-shelters).

Sensory deterrents: seed coating (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/modifying-mammal-access-to-trees#seed).

Vegetation management deterrents: vegetation control to reduce cover (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/modifying-mammal-access-to-trees#vegetation).

Occasional use

Physical exclusion from an individual tree or shoot: ‘natural’ physical protection (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/modifying-mammal-access-to-trees#exclusion-from-a-tree-or-shoot).

Any control must be conducted in line with animal welfare legislation such as the Wild Mammals (Protection) Act 1996 and the Animal Welfare Act 2006.

Managing trees in the landscape

Widespread use

Adapting planting pattern and choice:
- depth of hand sowing (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-trees-in-the-landscape#hand)
Occasional use

Adapting planting pattern and choice:
- timing of planting (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-trees-in-the-landscape#timing)
- planting diverse tree species (https://www.gov.uk/guidance/protecting-trees-from-mammal-damage-technical-guidance/managing-trees-in-the-landscape#diverse)
Additional information, guidance and resources

Case studies, trials, and scientific research

British Wildlife

A long-term study of the edible dormouse in Britain (https://www.britishwildlife.com/article/article-volume-22-number-3-page-153-161/).

Support, advice, and guidance

Forestry Commission

A guide to using tree shelters and guards (https://www.gov.uk/government/publications/tree-protection-the-use-of-tree-shelters-and-guards).