Pest Control
The British mice identification guide
Britain has several kinds of mouse, but only a couple cause trouble indoors. How to tell a house mouse from a wood mouse, and why it changes what you do next.
Britain has several species of mouse, but only a few ever come indoors, and they behave differently enough that knowing which one you have changes what you do about it. Here is how to tell them apart.
The short version
- The mouse in a town or suburban house is almost always a house mouse: greyish-brown all over, small ears, a strong musky smell.
- In rural homes, sheds and garages, wood mice (often called field mice) are common: sandy brown above, white underneath, big eyes and ears, long back feet.
- The yellow-necked mouse sometimes gets into houses in the countryside. The harvest mouse almost never does.
House mouse (Mus musculus)
Appearance. Greyish-brown on the back with a slightly paler, greyer belly, and no sharp line between the two. The body is about 7 to 9cm long, with a tail about as long again that looks almost hairless and scaly. Ears are smallish, eyes small, and the back feet are small compared with a wood mouse.
Behaviour. House mice live alongside people and rarely survive long away from buildings in Britain. They do not hibernate and breed all year indoors. They explore anything new quickly, which is why they are usually caught within days.
Smell. A strong, stale, musky smell from their urine is typical of an established house mouse problem.
Diet. They eat little and often, nibbling at many different foods, cereals in particular, rather than storing food. Scattered nibbling in food cupboards is a house mouse sign.
Wood mouse or field mouse (Apodemus sylvaticus)
Appearance. The most common mouse in Britain overall. Sandy or golden brown on the back with a white or pale grey belly and a clear line between them. Large dark eyes, large ears, long back feet for jumping, and a tail about as long as the head and body.
Behaviour. Wood mice live outdoors in woods, hedges, fields and gardens, and are nocturnal and very quick. They do not hibernate, and in autumn and winter they move into sheds, garages, outbuildings and the houses next to them.
Smell. Much less smelly than a house mouse.
Diet. Seeds, nuts, berries and insects. Wood mice cache food, so a pile of seeds or nuts hidden in a drawer, boot or loft corner is a classic wood mouse sign.
Yellow-necked mouse (Apodemus flavicollis)
A close relative of the wood mouse and similar in colour, but larger, with a yellowish band running right across the chest between the front legs. It is found mainly in southern England and along the Welsh borders, often near old woodland, and is a good climber. In autumn it will come into houses and lofts in rural areas. It is treated in the same way as a wood mouse.
Harvest mouse (Micromys minutus)
Britain's smallest rodent, weighing only a few grams, reddish-brown with a white belly and a tail it can grip with. Harvest mice live in tall grass, reed beds and hedgerows and build round woven nests above the ground. They are not a household pest and are very rarely found indoors.
Not a mouse at all?
- Shrews have a long, pointed, twitching snout and tiny eyes. Cats often bring them in. They eat insects, not stored food, and do not move into houses.
- Voles have a blunt, rounded face, small ears hidden in the fur and a short tail. They occasionally get into garages and sheds but rarely into houses.
- Young rats can look like a large mouse. A big head and thick tail, and droppings 12mm or longer, point to a rat.
Why the species matters
House mice live in the building and need treating and proofing. Wood mice and yellow-necked mice come in from outside, so proofing against the next autumn is the bigger part of the job. Either way, look for droppings, nibbled food and nests, and handle droppings with gloves after dampening them with disinfectant, never by sweeping or vacuuming them dry.
If you are not sure which you have, a photo of the mouse or its droppings next to a coin is usually enough for us to tell you. Our mouse control page explains how we deal with each.
More pest guides
Mice in the loft? How to spot them, and stop them
Light scratching overhead after dark, small droppings by the insulation. How to confirm it is mice, how they are getting in, and how to stop it for good.
Read the guide →Smells like trouble: dealing with dead rodents
A sour, sickly smell that moves from room to room is often a dead rodent in a wall or under a floor. How long it lasts, and how to deal with it safely.
Read the guide →Not sure what you're looking at?
Send us a photo or describe it. We will tell you what it is, whether it needs treating at all, and what it would cost, before anyone comes out.