Living Organisms / Animalia / Craniata / Mammalia / Rodentia / Muridae / Mus / Species
Mus musculus - House mouse (Click photographs/illustrations: full picture & further details)
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General and References

Alternative Names (Synonyms)

  • Grey mouse
  • Souris domestique (French)
  • Hausmaus (German)
  • Westliche hausmouse (German)
  • Mus molossinus (B51)
  • Mus castaneus (B51)
  • Mus poschiavinus (B51)

Ancestor of Mus domesticus - Laboratory mouse

Names for new-borns / juveniles

Names for males  
Names for females  

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General Appearance

Typical mouse with large eyes and ears, long naked tail, pointed muzzle; dull grey-brown (B142, D30).

Similar Species

Distinguished from Apodemus flavicollis - Yellow-necked mouse and Apodemus sylvaticus - Wood mouse by shorter hind feet, narrower head and smaller eyes, also slightly thicker and more obviously scaly tail (B142, D30).
Sexual Dimorphism --

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Species Author

Debra Bourne

Major References

Husbandry references:

B151, B169.24.w24

(UK Contacts)

(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

  • --

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TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

  • Mice (Rodents)

Specific Needs Group referenced in Management Techniques

  • Mice (Rodents)

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Husbandry Information


  • Wild rodents may carry diseases transmissible to humans. Care should be taken in all handling of wild rodents. (B169.24.w24)
  • Wild rodents are liable to bite. (B169.24.w24)
  • Wild rodents are generally less stressed by indirect (e.g. being tipped gently from one container into another) than direct handling. (B169.24.w24)
  • Wild rodents are less stressed if handled in reduced light conditions (B169.24.w24).
  • Domestic rubber gloves provide protection against excreta and urine and also some protection against mouse bites, as the slight gap between the glove and the finger generally stops bites from penetrating the skin. (B169.24.w24)
  • Wild mice may be held by the middle or base of the tail. (B169.24.w24)
  • Holding by the tail tip is not recommended: the skin at the tip may slough off. (B169.24.w24)
  • To catch from within a cage or box, place the cage/box within a large rectangular container with sides at least 45cm high and smooth. Remove the lid of the cage/open the box and allow the mouse to run out, then remove the cage/box. Guide the mouse into a corner of the container and cup a hand over it (not gripping the mouse), then pick the mouse up by the middle of the tail using the other hand. If allowed to rest the feet on a solid object the mouse will generally pull away rather than turn and bite. (B169.24.w24)
  • Accommodation: provide nest box, and bedding such as shavings, hay, shredded paper sufficient for burrowing in. Cage cleaning should be required only about every two weeks and should not be more frequent than necessary due to the disturbance related to the loss of odour cues (B169.24.w24).


  • CO2/O2 until loss of consciousness, then increase CO2 to 100% and keep there for at least 10 minutes. N.B. neonatal rats and mice are relatively resistant to CO2.
  • Stunning
  • Decapitation
  • Lethal dose of inhalation anaesthetic e.g. halothane (B169.24.w24).
Individual Techniques linked in Wildpro

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Appearance / Morphology

Measurement & Weight

Length Head-Body length: 70-93mm (D30); 75-93mm (B142); 65-95mm (B147).
Height --
Adult weight General 13.4-18.2g (B142); 12-20g (B147).
Male --
Female --
New-born weight About 1 gm (B147).
Growth rate --

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General --


Nose: pointed muzzle (B142).

Ears: Large (B142).

Dentition (Teeth) --
Eyes --

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Legs and Tracks

Hind foot length: 16.8-18.4mm (B142).

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  • Uniform brownish pink, scaly. Slightly less long than head-body length (D30).
  • Commensal forms tail usually longer than wild forms (B147).
  • Length: 71-84 mm (B142); 60-105mm (B147).

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Coat / Pelage

Adult Female Dull, greasy, with short kinked underhairs and longer straight overhairs.
  • Dorsal: uniform grey-brown
  • Ventral: slightly paler grey-brown


Dorsal light brown to black, ventral white or washed buffy (B147).

Variations (If present)
  • Various: black, black-eyed white, albino, leaden, cinnamon, also ventral white spotting or ventral white (B142).
  • Commensal forms generally darker than wild forms (B147).
Moult Periodic waves of moult, no clear seasonal moult (B142).
New-born / Juvenile --

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Neonate (New-born) Characteristics

Blind, naked, pink (B142, B147).

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Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Reproductive: usually five pairs of nipples, prominent in lactating and old females. Prepuce of male relatively long (B142).

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Life Stages / Natural Diet / Physiology

Reproductive Stages

Breeding Season
  • Year round indoors, during summer outside (B142). 
  • Mainly temperature controlled, may also be role of food availability. Not photoperiod dependant (B142).
  • Year round, April to September in wild in Britain (B147).
Oestrus / Ovulation
  • Oestrus cycle 4-5 days; oestrus within 24 hours of parturition (B142).
  • Oestrus cycle 4-6 days, oestrus less than one day, post partum oestrus 12-18 hours after parturition (B147).
Gestation / Pregnancy
  • 19-20 days, longer if lactating (may be 36 days) (B142).
  • 19-21 days, longer if lactating (B147).
Parturition / Birth --
Neonatal development
  • Birth: naked, pink, blind.
  • 2-3 days: eyes open,
  • 5-7 days: skin pigmentation visible.
  • 8-10 days: hair half grown.
  • 14 days: hair grown, incisors erupted, weaned
  • (B142)

Birth: blind, naked; 10 days furred, 14 days eyes open, 3 weeks weaned (B147).

Litter size
  • 5 to 8, mean 6.5 to7.5; early litters smaller than later litters (B142).
  • 3-12, usually 5-6 (B147).
Time between Litters / Litters per year
  • About one month between litters (B142).
Lactation / Milk Production
  • About 14 days (B142).
Sexual Maturity
  • Females breeding span 6-12 months, males about 18 months (B142).
  • Lifespan of more than two years common for mice commensal with humans; wild-living mice "rarely survive two winters" (B142).
  • 60-70% mortality before independence (B147).
  • Average life in laboratory 2 years, may reach 6 years (B147).

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Natural Diet


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Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Temperature --
Pulse --
Respiration --
Faeces --
Haematology / Biochemistry --
Chromosomes 2n = 40 (B142).
Other --

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Feeding Behaviour


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Parental Behaviour


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Social Behaviour / Territoriality

  • Males often disperse from natal area at 1 to 2 months old (B142)
  • More than 20% of both sexes breed at site different from birth area.
  • Generally little movement between breeding groups (B142)
  • Flexible social system (B142).
  • Initial mutual retreat on strange territory, later encounters one holds ground and makes aggressive movements towards retreating animal.(B142)
  • Territory-holding males frequently fight (B142).
  • Territorial and colonial in commensal and laboratory conditions (B147)
  • Wild populations territoriality less obvious (B147).
  • Territories stable once formed. (B147)
  • Usually dominant male and several females, sometimes with subordinate males. (B147)
  • Sometimes equal sharing of Dominica by several males (B147)
  • Forced dispersal of juveniles in wild non-territorial and territorial commensal populations (B147)

(B142, B147).

Inter-specific --

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Sexual Behaviour


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Predation in Wild

Rats, owls, small carnivores (B142).

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Activity Patterns

  • Movements of 400m not infrequent and of 1km or more recorded (B142)
  • Less active (as indicated by decreased trapping) on moonlit nights and when food plentiful (B142).
  • Burrow well in soft earth (B142).
  • Good at climbing and jumping.
  • Swim well.


  • Mainly nocturnal.
  • Periods of activity 1-4 hours.

(B142, B226)

  • Commensal forms may be active any time (B147).

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Habitat and Range

General Habitat Type

  • Houses, agricultural buildings, food stores, agricultural areas (B142, D30)
  • Originally probably rock crevices.
  • In Britain mainly avoid open fields without cover, and generally rare in woodland (B142).
  • Woodlands and very dry areas generally avoided (B143).
  • Generally commensal with humans, but found in wide variety of habitats (B143).
  • Highly opportunistic but weak competitors (B143).
  • Cracks in rocks or walls, and underground burrows (B147); also in buildings (B147)

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Nests / Burrows / Shelters

  • Nests variable: simple pallet to enclosed sphere.
  • Any convenient material used for construction - rags, paper or similar, with finer shredded material for lining.
  • Burrows vary simple to complex with one or several chambers. 2 to 3cm diameter

(B142, B147).

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Distribution and Movement (Migration etc.)

Normal Original: Nepal west to north Africa, western and southern Europe (B142); probably India, with extension into Mediterranean region and central Europe to Japan (B147)
  • Britain: widespread, including most inhabited islands (B142).
  • World range: Mus domesticus Europe (western and southern mainland, Mediterranean islands, British Isles, Faeroes), also Asia from Turkey to Iran, southwards to North Africa. (B143).
Occasional and Accidental --

Extended range by association with humans; now worldwide as commensal (B147).

  • North America. South America, Australasia, south-east Africa, oceanic islands.

(B142, B143)

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Intraspecific variation

Sometimes considered separate species Mus domesticus, sometimes subspecies Mus musculus domesticus (B143).

Three subspecies of Mus domesticus described: Mus domesticus domesticus, Mus domesticus brevirostris Waterhouse, 1837, Mus domesticus praetextus Brants, 1827 (B143).

Karyotypes with chromosome number reduced by chromosome fusion occur (B143).

Four different sub-species of Mus musculus (B147):

  • Mus musculus musculus: wild-living mouse of northern Asia and eastern Europe.
  • Mus musculus bactrianus :commensal, south-central Asia.
  • Mus musculus domesticus (sometimes considered distinct species): commensal, western Europe, northern Africa, south-western Asia. Narrow hybrid zone where overlaps with Mus musculus musculus in southern Denmark, along River Elbe, and through south-eastern Europe to Black Sea
  • Mus musculus castaneus (sometimes considered distinct species): commensal, south-eastern Asia. Broad intergradation zone with Mus musculus musculus in eastern Asia and Japan.


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Conservation Status

Wild Population -
  • Common, pests (B143).

  • In Britain: introduced to Britain by the Iron Age, this species is locally abundant. Pre-breeding population estimate of about 5,192,000, including 4,535,000 in England, 657,000 in Scotland, 206,000 in Wales. Population estimate was made with little information available; data believed to be "within the right order of magnitude". Figures considered minimums.(B221)

General Legislation --
CITES listing --
Red-data book listing --
  • Limited by competitor species in non-commensal situations (B221).
Captive Populations --
Trade --

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