The house mouse

Lat: Mus musculus.

A grey mouse with a slightly lighter underside. Together head and body measure 8 – 9 cm, while the tail is a little shorter. It originates from southwest Asia, but is now widely spread around the world. It adapts easily and is found wherever people live. In the summer many house mice live in fields, but most seek houses in the autumn. This takes place from mid-August and the biggest invasions takes place in mid-September.

Inside buildings mice live wherever they can find food and nesting material. House mice can survive without drinking water and therefore thrives well in granaries, mills and warehouses. Nests are built in hidden places and are disordered piles of available materials. Both rock wool and glass wool are excellent materials for nests. House mice can survive in rooms with temperatures below the freezing point, as long as there is sufficient food and nesting material. There are even examples of house mice breeding in deep freezers.

House mice breed all year round and can give birth to a dozen litters a year. Although house mice are omnivores, they prefer seeds, especially cereals and cereal products. A house mouse can eat 3 grams of food per day. The house mice do not have fixed feeding points (as rats do), but they eat more randomly in small quantities and in many different places. The result is that they contaminate and destroy more than they actually eat.

Mice contaminate food with urine and droppings. A large mouse population can destroy packaging, electrical appliances etc.

House mouse

( Latin: Mus musculus)

Many house mice spend the summer out in the fields, but usually not far from houses. Then from the middle of August onwards they start to move indoors again, and the peak of such an invasion will usually be in the middle of September. See also p. 84 for more details on house mice.

House mouse

( Latin: Mus musculus)

The house mouse came originally from south-western Asia. It has spread to all parts of the earth, mainly with the help of man. It has an amazing ability to adapt and it now occurs more or less wherever man has settled.

In most areas this mouse is associated with buildings, often moving out into the fields in summer, but almost always retreating indoors in autumn.

In buildings these mice will establish themselves wherever they can find sufficient food and nest material. They live mainly in lofts, under floors and in cavities in masonry, whence they gnaw their way through wooden partitions into kitchens and other places where they can find food.

The nest is always built in a sheltered position, and it consists merely of an irregular mass of any available material, such as cloth, wool or paper.

When conditions are favourable, house mice can breed throughout the year, producing up to ten litters in that period, but more usually no more than five or six. House mice are omnivorous but they prefer seeds, particularly cereals and cereal products, but when these are lacking they will feed on the strangest things, such as soap, wax candles and putty. An adult mouse eats about 3 grams of solid food a day, which corresponds to 70-100 grains of wheat, but they destroy many more because ‘they seldom consume the whole grain. In fact the main damage done by mice is to foul goods with urine and excrement and to destroy sacks and other packing by gnawing through them.

They also damage many other things by gnawing them, as for example timber, insulating materials, paper and textiles.