Scientific Name: Mus musculus domesticus.
English Name: House Mouse.
French Name: La Souris grise (='grey mouse').
5 Key Characters:
- Head and body 7 - 10 cm; tail 7 - 10 cm; weight 12 - 22 g.
- Rather small and slender compared to other rats and mice.
- Grey or grey-brown.
- Sharply pointed muzzle.
- Mainly nocturnal, but also active during the day.
Lookalikes: Wood Mouse Apodemus sylvaticus, which has larger ears and a more definite division of grey fur on the upper body and white on the belly.
Habitat: Houses, farms, warehouses, where the species eats all kinds of foodstuffs. Favours farms or houses where there is pet food. Also fields, shrubs and open woods. They often make their nest in stored food, which they spoil with their excrement. Will also nibble textiles, plastics, paper, electrical cable, etc, which adds to the damage they do. Modern buildings are less favourable to the species. Lives in large family groups. Digs tunnels.
Active Period: All year, but most abundant in the autumn. Nocturnal. Climbs and swims well. Litters of 5 - 8 young are born at monthly intervals.
Status: Ubiquitous, common but declining. After man, the most widely distributed species on the planet. For all that, it is widely unrecorded and unobserved, but undoubtedly less numerous than in the past, due to less favourable habitat being available, modern farming techniques and rodent control methods. In the past they were the third most common small mammal of arable land (after wood mice and bank voles). Modern harvesting practices have removed their winter habitat and today they are more associated with pig and poultry barns or grain stores and is now rarely found in open countryside. Does not thrive if there is competition from Wood Mice or Common Rats Rattus norvegicus. House Mice are prey for Common Rats and are vulnerable to cold weather, frosts and subsequent shortages of food.
Photographed by Loire Valley Nature: