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House mouse

Mammal

Mus musculus

This tiny rodent has greyish fur, large ears, a pointed snout and a long, scaly tail. Apart from humans, it is probably the commonest mammal in the UK.

It is a nocturnal creature and is often considered a pest, as it spoils food and carries disease. Mice are quite aggressive towards each other and fights are frequent.

They construct a system of tunnels to live in, which may be quite simple or more complex with several chambers and exits. Females are able to produce up to 10 litters in a year, each with between four to eight young. Within three weeks of birth, the young mice are independent.

The wood mouse Apodemus sylvaticus appears rather similar, but has more orange-brown fur and large, protruding eyes. This mouse is common in woods, hedgerows and scrub. It is a good climber and is often found in trees. It also enters houses in search of food.

What does it eat?

Grain, seeds, roots, fungi and insects. Inside the house they seem to eat almost anything!

When will I see it?

At anytime of the year. Tends to come in the house during the winter months.

Where will I see it?

Around log piles, outbuildings, patio pots; sometimes in the house. Also on farmland.

Vital statistics

Length: Up to 10cm, tail up to 10cm
Weight: Up to 20g

Calendar

Seen in JanuarySeen in FebruarySeen in MarchSeen in AprilSeen in MaySeen in JuneSeen in JulySeen in AugustSeen in SeptemberSeen in OctoberSeen in NovemberSeen in December

Key to calendar