How to fight mice in your home

Mouse in the home? Protect yourself from current and future mice. Tips for effective control in the kitchen, basement and living room.

If you have had an unexpected visit from a mouse indoors, it could be one of two species:
- The house mouse (Mus musculus)
- The Yellow-necked mouse (Apodemus flavicollis).

Other species of mice can also stray into our houses, but they rarely thrive for very long at a time.

Adult house mice and collared mice are relatively different, so they should be quite easy to tell apart.

House mouse

The house mouse in Denmark can be found in two forms. A single-coloured dark gray mouse that is particularly found in South Jutland and West Jutland. As well as a mouse with gray on its head and a light underside on its back. The mouse is typically between 8-9 cm, the length of the tail is slightly less.

The house mouse is common throughout Denmark. In the summer, many house mice stay around and in gardens, green areas and along and in fields. However, they never stray very far from inhabited areas and houses. At the beginning of autumn, they enter our warm houses, as very few house mice are interested in wintering outdoors. You actually understand that very well :)

When it lives indoors, it can reproduce throughout the year with 4-8 young spread over 4-6 litters during a calendar year.

Yellow-necked mouse

The yellow-necked mouse is characterized by a dark brown upper side. The underside is white, very white, with the exception of a brown "band" in front of the mouse's front leg. The collared mouse is larger than the house mouse, as the mouse's body is 10-12 cm., while the tail is longer than both head and body combined. Unlike the house mouse, the collared mouse is not a frequent visitor on the west coast of Jutland. It stays more in the country's forests, but can also be found in parks and gardens with shrubbery.

If you live near forests and large green areas, there is a greater probability of visits by the collared mouse. Unlike the house mouse, the yellow-necked mouse stays outside all year. However, some enter our houses later in the autumn. The mouse will often make a nest inside, but will only start breeding when it comes out into the open again. So the probability of having baby collared mice indoors is minimal.

Damage due to mice

Both the yellow-necked mouse and the house mouse are very mobile. Both mice are thus excellent climbers, and a young house mouse can easily squeeze through a small crack - even if it is significantly smaller than the mouse itself. The house mouse's need for liquid is very small. It can do well in grain storage, mills and warehouses or similar locations. Both types of mice eat EVERYTHING – omnivores. In typical detached houses and similar dwellings, the mice have burrows and nests in the insulation, on vents and under floorboards etc. They typically place their nests near the kitchen. House mice and collared mice eat respectively. approx. 3 grams and 6 grams of food during the day. It doesn't seem like much at first, but you should be aware that it does a lot of damage in its attempts to find food. Among other things by gnawing on bedding, curtains, furniture, woodwork etc.

In addition, mice building nests indoors can cause damage to electrical installations, and can in some cases cause short circuits and fires. In addition, contamination of food with excrement and urine can involve a certain risk of infection for humans.

Prevention and control

A good tip is, as always, to secure the buildings so that the mice cannot enter the houses or the like. However, even the most solid houses can have weak points, which the mice quickly exploit to their own advantage. However, it is a good idea to make sure that the basement windows are closed, and to ensure that all the windows are intact, as the mice are not stupid, and will use all imaginable entrances, such as via a partially broken window. It is also smart to ensure that all ventilation openings are equipped with fine-mesh galvanized wire mesh or mouse protection.

You should also be aware that all pipe passages are closed, and that the doors can be closed completely and that there is no vegetation on the building's outer walls. Easy access to food and feed means that the mice thrive and can therefore reproduce in their nests in the houses. Therefore, a good tip is to store all food in either refrigerators or closed containers that the mouse cannot gnaw through. That's why plastic foams. Use metal or glass containers instead. Also, be aware that your waste is not easily accessible to the mice. This applies particularly around holiday home areas and areas that have previously been plagued by mice.

It is recommended to have the small and slightly larger loopholes closed in connection with a mouse infestation. A temporary closure can be made with compressed fine-mesh metal mesh or steel wool, which can be placed in the holes to prevent the mice from using these entrances and loopholes. If the mice are already in the house, you can remedy the problem by using various traps. Note that using mouse poison indoors can result in dead mice in inaccessible places, which attract other pests and insects. Thus, poison indoors will often just mean a new problem.