Dormice are approximately ten species of rodents that make up the family Gliridae. Dormice typically live in trees, bushes, hedgerows, gardens, and rock piles. Dormice have a superficial resemblance to squirrels (family Sciuridae), but they are smaller and differ in many other anatomical and behavioral characters.
Dormice have soft fur, and a long, bushy tail. Their forefeet have four digits, the hindfeet have five, and all have claws that aid in climbing. If a predator grabs a dormouse by the tail, that appendage is shed, giving the dormouse a chance to escape. Dormice are nocturnal animals, mostly foraging on plant materials, but also opportunistically taking arthropods and the contents of bird nests. In fact, in some places predation by dormice is believed to cause significant reductions in the populations of breeding birds.
Dormice become quite fat by the end of the autumn, approximately doubling their normal summer weight. Dormice spend most of the winter sleeping in their nest, except for relatively warm and sunny days, when they awake and eat food that they have stored.
The fat dormouse (Glis glis) is a rather arboreal species that occurs widely from Spain and France to western Russia, and has been introduced to southern England. The usual natural habitat is angiosperm and mixedwood forests. However, the fat dormouse also occurs in proximity to rural and suburban humans, and often nests in buildings. The fat dormouse is sometimes considered an important agricultural pest, especially in orchards where they may eat large quantities of valuable crops such as walnuts, or take small bites out of large numbers of softer fruits, making the produce unsalable. They are particularly regarded as a problem in Britain, where the populations of these animals are not well controlled by natural predators.
The fat dormouse is the largest of the dormice and it is sometimes eaten by people, some of whom consider the flesh of this animal to be a delicacy. In some respects, this epicurean taste for the fat dormouse is a leftover from the cuisine of the ancient Romans, who used to breed this dormouse in special pens for consumption when the animals were at their fattest.
The hazel mouse, or common dormouse (Muscardinus avellanarius) is the smallest species in this family, and occurs through much of Europe, Asia Minor, and western Russia. The usual habitat of these arboreal animals is forests and hedgerows, especially if there is a dense canopy of shrubs.
The garden, or orchard dormice (Eliomys quercinus and E. melanurus) occur in Europe, western Russia, Asia Minor, and northern Africa. These animals live in forests, swamps, and rocky habitats.
The tree, or forest dormouse (Dryomys nitedula) occurs in forests and shrubby habitats of much of Europe and Asia Minor. The Japanese dormouse (Glirulus japonicus) only occurs in montane forests on the islands of Japan in eastern Asia. The mouse-like dormouse (Myomimus personatus) is a rare species that is only known from a few specimens collected in central Asia and Asia Minor. The African dormice (Graphiurus spp.) are three species that occur in a wide range of habitats in sub-Saharan Africa.