Facts About Dormice

FFacts On Tap Editorial Team Fact-checked Updated April 12, 2025 3 min read

Dormice are small, round-bodied rodents best known for spending much of the year fast asleep. With their big dark eyes, bushy tails, and thick fur, these woodland dwellers are among Europe's most charming and least-seen mammals.

Here are the real facts behind these tiny hibernators, from their family tree to their unusual sleep habits.

Dormice belong to the rodent family Gliridae (also called Myoxidae), which contains roughly 27 to 29 living species, depending on the classification used.
Gliridae species are native to Europe, Africa, and Asia, including several found in the United Kingdom.
Dormice are agile climbers and are typically found in deciduous woodlands, hedgerows, and overgrown gardens.
One of the best-known species is the hazel dormouse (Muscardinus avellanarius), native to much of Europe and part of the UK's protected species list.
Dormice are omnivores, eating flowers, fruit, nuts, and occasionally insects or bird eggs when other food is scarce.
Dormice are true hibernators, often sleeping for six months or more each winter, curled into a tight ball to conserve energy.
During hibernation, a dormouse's body temperature and heart rate drop dramatically as it enters a deep state of torpor.
Dormice have a thick, soft fur coat, and unlike most rodents their tails are covered in fur rather than being scaly.
Hazel dormice usually have one litter a year, averaging around 4 pups (occasionally 1 to 7), typically born in mid to late summer.
Wild hazel dormice often live only 3 to 4 years, though individuals in captivity have been recorded living up to 6 years.
The name 'dormouse' likely derives from the French 'dormir' (to sleep) or Latin 'dormire', reflecting their famously long hibernation.
The hazel dormouse is a European protected species, and in the UK it is legally safeguarded due to sharp population declines linked to habitat loss.
Dormice build spherical nests out of shredded bark, leaves, and grass, often woven into shrubs or tree hollows.
Because they are nocturnal and rarely seen, ecologists often survey dormice using specially designed nest boxes and "dormouse tubes" rather than direct sightings.

Frequently asked questions

Are dormice endangered?

Several dormouse species, including the hazel dormouse, are in decline and are legally protected in parts of Europe, though "endangered" status varies by species and region. Habitat loss and fragmentation are the main drivers of these declines.

How do dormice hibernate?

As temperatures drop and food becomes scarce in autumn, dormice curl into a tight ball, often underground or in leaf litter, and enter torpor. Their heart rate, breathing, and body temperature all drop sharply, allowing them to survive for months on stored fat.

Do dormice make good pets?

Wild dormice are not suitable as pets and, in the case of the hazel dormouse, are legally protected from capture or disturbance in much of Europe. Some non-native species, like the African pygmy dormouse, are sometimes kept as exotic pets, but this is a different matter from taking a wild animal.

What are the main threats to dormice?

Habitat loss and fragmentation of woodlands and hedgerows are the biggest threats, since dormice rarely cross open ground and need connected tree cover to move, feed, and nest safely.

How can I help protect dormice?

Supporting hedgerow and woodland restoration, maintaining connected tree cover in gardens, and backing local wildlife trust conservation projects all help protect dormouse populations.

Where can I learn more about dormice?

Organizations such as the People's Trust for Endangered Species, the Woodland Trust, and national wildlife trusts publish detailed, up-to-date information and run active dormouse conservation and monitoring programs.

Sources & further reading

Reviewed by the Facts On Tap Editorial Team

We write every article to be genuinely fun — and genuinely true. Each fact is checked against reputable sources before it goes live. Spotted something off? Tell us and read our fact-check policy.

More animal facts

View all →

Animal Facts

Facts About Birds

Discover verified facts about birds: the fastest flyer, the tiniest species, the oldest parrot on record, and how these feathered dinosaurs took to the sky.

Fact-checked·13 facts