Here we provide general information on the housing and husbandry requirements of commonly used laboratory rodents, including mice, rats, guinea pigs, gerbils and hamsters. More detailed guidance can be found in the resources and references provided.


Basic requirements

Basic requirements for good rodent housing and husbandry are given in the table below.

Housing in stable, compatible groups – it is important to take into account sex, age, reproductive condition, familiarity, prior group housing experience when grouping the animals.

Enclosures designed to cause minimum disturbance to the animals.

Enough space for exercise, normal social behaviour (e.g. grooming, play) and the provision of environmental enrichment to help reduce the risk of social stress and aggression and allow the animals to fulfil some of their species-specific behaviours. The enclosure should be arranged in a way that allows for compartmentalisation of space.

Enough height for rearing on the hind legs for scanning, exploration and play – at least 12cm for mice, 18cm for gerbils and hamsters, and 30cm for rats.

Solid floors with an adequate depth of an appropriate substrate (e.g. 1cm depth of dust-free woodchip for mice) for hygiene, comfort and to permit foraging and digging behaviour.

Material to gnaw (e.g. nylon chews, soft wood blocks, hard pellets, cardboard tubes) to prevent the teeth overgrowing, for enrichment and to prevent stereotypic bar chewing.

Refuges (e.g. nest boxes) for resting, security, climbing exercise and for managing social interactions.

Vertical barriers or tubes (e.g. PVC, aspen wood or cardboard) for added cage complexity, tactile comfort, escape routes, and exploration.

Nesting material (e.g. soft paper or soft wood) for comfort, to help regulate temperature and light levels, and to hide and retreat from cage mates or threatening stimuli. Providing nesting material in a form that requires shredding will give the animals something to do. Nesting material is essential for parturient females. Nest boxes should be provided if insufficient nesting material is provided for the animals to build a complete, covered nest.

Appropriate lighting levels and regimes. Within the enclosure, lighting should be soft or diffuse, rather than direct. Areas of low light should be provided within the cage (e.g. racks with shaded tops, shelters, nesting material). The option to retreat into a shaded area reduces the risk of retinal degeneration in albino animals.

A varied diet and the ability to forage – scattering food (e.g. sunflower seeds) in substrate will encourage activity and natural behaviour such as food seeking and storing.

Minimisation of extraneous noise and ultrasound.

Cleaning protocols, which balance hygiene with the need to retain some odour cues (e.g. scent-marked nesting material) to avoid stress and aggression.

Gentle and frequent handling from early in life.

Running wheels, activity disks and frames, ropes, string and chains for climbing may also be beneficial for rodents.

Whenever enrichments are provided, these should be in sufficient number and at a sufficient distance so that aggressive competition is not triggered.


The laboratory mouse is derived from the wild house mouse (Mus musculus), a largely nocturnal burrowing and climbing animal which builds nests for regulation of the microenvironment, shelter and reproduction. Mice do not readily cross open spaces, preferring to remain close to walls or other structures. A wide range of social organisations has been observed depending on population density, and intense territoriality may be seen in reproductively active males. Pregnant and lactating females may aggressivley defend their nests. Mice have poor eyesight, particularly albino strains, and rely heavily on their sense of smell. They scent marking their environment within urine. Mice also have very acute hearing and are sensitive to ultrasound. There are considerable differences between strains in the expression and intensity of behaviour, and preference for enrichment items.

Individually ventilated cages

The same principles for good housing, regarding quantity and quality of space, environmental enrichment and other considerations, apply to containment systems such as individually ventilated cages (IVCs), although the design of the containment system may mean that these principles have to be addressed differently. The draught induced by high intra cage-ventilation rates in some IVCs can induce chronic stress and heat loss. The location of the air supply to the cage (e.g. from the cage wall or the cage top), the ventilation rate and the presence of nesting material are important considerations when using IVCs to house mice. Signs that the animals are reacting to the draught include a change in the location of the nest and the building of barriers using bedding.

Further information about the housing and husbandry of mice is available on our dedicated page.


The laboratory rat is derived from the wild brown rat (Rattus norvegicus) and is a highly social animal. Rats avoid open spaces, and use urine to mark their territory. Their sense of smell and hearing are highly developed, and rats are particularly sensitive to ultrasound. Daylight vision is poor, but dim-light vision is effective in some pigmented strains. Albino rats avoid areas with light levels over 25 lux. Activity is greater during hours of darkness. Young animals are very exploratory and often engage in social play.

Further information about the housing and husbandry of rats is available on our dedicated page.

Guinea pigs

Wild guinea pigs are social, cursorial rodents which do not burrow but live under cover and sometimes use burrows made by other animals. Adult males may be aggressive to each other but generally aggression is rare. Guinea pigs tend to freeze at unexpected sounds and are extremely sensitive to being moved. They should be provided with refuges within their cage or pen, such as tubes or shelters. Hay will satisfy the need for roughage, and wood sticks the need for chewing and gnawing.

Further information about the housing and husbandry of guinea pigs is available on our dedicated page.


The gerbil or Mongolian jird (Meriones sp.) is a social animal and is largely nocturnal, although in the laboratory it is also active during daylight. Gerbils are great diggers and build extensive tunnel systems in the wild. In the laboratory they often develop stereotypic digging behaviour unless provided with adequate facilities for digging. For this reason gerbils need comparatively more space than other rodents in order to allow them to build and use burrows of sufficient size. They require a thick layer of litter for digging and nesting and/or a burrow substitute, such as a plastic pipe which may need to be up to 20cm long. Nesting material (e.g. hay, straw, etc.) and wood sticks can be used for chewing and gnawing.

Further information about the housing and husbandry of gerbils is available on our dedicated page.


Hamsters are burrow digging, nest building rodents. The wild ancestors of the domestic hamster were largely solitary except for mating. Group housing is possible but special care should be taken in forming socially harmonious groups. Compatible groups of animals will sleep and huddle together. Environmental enrichment should include nesting material, a refuge area (e.g. tube, plastic shelter), roughage and gnawing objects. Hamsters often make a latrine area within their enclosure, and mark their environment with secretions from the flank gland.

Related resources

Refinement of Housing and Handling Conditions and Environmental Enrichment for Animals Kept in Laboratories Animal Welfare Institute Database
Rodent Welfare Group meetings RSPCA/UFAW 
Laboratory Animal Refinement and Enrichment Forum (LAREF) Animal Welfare Institute. For exchange of information and experiences on ways to improve laboratory animal housing and care Stanford University. A wiki ethogram for the laboratory mouse

IAT Congress 2017 workshop summary: Playtime for Rats NC3Rs/AstraZeneca

Validating refinements to laboratory housing: asking the animals. NC3Rs invited article. Sherwin C (2007) 
View PDF
Refinement of rodent research through environmental enrichment and systematic randomization. NC3Rs invited article. Würbel W, Garner JP (2007) 
View PDF
Making sense of scents: reducing aggression and uncontrolled variation in laboratory mice. NC3Rs invited article. Hurst J (2005) 
View PDF


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Information provided by Vera Baumans, University of Utrecht
Last updated: June 2013