Dull greyish brown dorsal colour, with slightly lighter venereal surface broadish head with large eyes. Tail thicker and more scaly than other mice. Females larger than the males. Sizes vary but average 85mm with the tail averaging 73mm. The average weight is 16g
House mice have been present in Britain since at least the iron age where they came from their original habitat of Iran and SouthWest USSR. In the UK they live in habitats such as buildings and food stores. Deep litter poultry house where they can form huge densities and houses. hey are rarely found in woodland and avoid open fields but in North West Scotland and the Hebrides they will colonies agricultural land.
The House Mouse is mainly nocturnal except in dense populations. The nest vary from a simple pallet to an enclosed sphere which is made from any conventional material. The burrowing system they use can from a simple 2 to 3 cm diameter tunnel to a complex system of tunnels and chambers 10cm in diameter often lined with bedding material. They have an excellent sense of balance and considerable climbing ability and can move up wooden or brick wall with very little difficulty and are excellent swimmers.
The House Mouse will eat most foods but prefer cereal grains over foods that contain fats and protein. Insects also form a substantial part of their diet.
Litters of 5 to 8 are born at about monthly intervals throughout the year to females that become sexually mature at 5 to 6 weeks after birth. The breeding span of a female house mouse is 6 to 12 months. The mean life expectancy of a wild house mouse is about 100days but some do rarely survive 2 winters.
A House Mouse can eat 4g of food per day but its eating habits are very wasteful and can waste more than 10 of its food. Moreover a House Mouse produces over 50 dropping a day and they can be very difficult to remove during the course of food production. In 1972 it was estimated that 9% of houses in London were infested by House Mice.
House mice are offered no legal protection. Indeed active research into their control was begun in the second world war when it was realized that the mice were causing serious damage to stockpiled food stuffs. Most controls involve poisoning with warfarin based poisons but these received a serious setback with the spread of inherited resistance to this type of poison.
Corbet, G.B. & Harris, S. (1991) The Handbook of British Mammals. (3rd edn.). Blackwell, Oxford.