Animal Housing




Animal housing will follow the recommendations in the Guide for the Care and Use of Laboratory Animals (8th edition or more current) or the Guide for the Care and Use of Agricultural Animals in Research and Teaching (4th edition or more current). Social housing should be the default method of housing for social species of animals unless otherwise justified or exempted by IACUC policy, as outlined in the “Exceptions” section below. This justification must be approved by the IACUC and should be based on scientific necessity or on social incompatibility resulting from inappropriate behavior or veterinary concerns regarding animal well-being.

When single housing of animals is deemed necessary, this housing configuration should be limited to a minimum period of time. If possible, visual, auditory, olfactory, or tactile contact should be provided with other conspecifics during the period of single housing. Singly-housed animals should be offered additional enrichment provided on a species-appropriate basis, such as supplemental enrichment items, interaction with research or animal care staff, or exercise in a space other than the primary enclosure. The requirements set forth in this policy also pertain to investigator-maintained animal colonies.

Animals that are singly housed within DAR facilities must have a label on their housing unit identifying the reason for single housing. Please see the Guideline for information on this labeling requirement.


Appropriate housing promotes species-typical behaviors, enhances the overall well-being of animals, and supports quality in research and education. Animals require an environment that permits them to grow, mature, and maintain good health and species-specific behaviors while minimizing experimental variation. An appropriate housing space or enclosure should account for the animals’ social needs. Social housing promotes basic behavioral needs and contributes to the psychological wellness of many animals. Therefore, social animals should be housed in stable pairs or groups of compatible individuals unless they must be housed alone for experimental reasons or because of social incompatibility. Any species or specific groups within a species that would live as groups in a natural or free-range habitat should be considered social animals. Structural adjustments are frequently required for social housing (e.g., perches, visual barriers, refuges), and important resources (e.g., food, water, and shelter) should be provided in such a way that they cannot be monopolized by dominant animals. 


Social Housing Exceptions That Require IACUC Approval

Experimental Requirements: Social housing may confound scientific goals in some types of research. If an investigator believes that social housing may affect their research objectives, the investigator must request an exception in an IACUC protocol. In the protocol, the PI must include a scientific justification and a specific description of the housing arrangement. When single housing of animals is deemed necessary it should be limited to a minimum period of time. IACUC approval is required before exceptions to social housing can be implemented.

Strain or Group-Specific Aggression: If social incompatibility is a trait of a specific strain or specific groups within a strain or species, the need for single housing must be described and justified in the IACUC protocol. 

Individual Housing Situations That Do Not Require IACUC Approval

Veterinary Concerns: Temporary exceptions may be approved by the Attending Veterinarian or veterinary staff for social aggression, animal health or other medical reasons. Veterinary staff recommendations for single housing may be made when an animal exhibits vicious or overly aggressive behavior after failed group housing attempts with cohorts that would typically be compatible. These exemptions are handled on a case-by-case basis by veterinary staff.

Standard Animal Management and Husbandry Practices: These standard practices do not constitute an exception to this policy. Examples include, but are not limited to:

  • Standard agricultural husbandry practices, such as the use of farrowing or gestation crates in sows, and individual housing of intact males (i.e. stallions, boars).
  • Temporary single housing of animals post-operatively, up to 72 hours.
  • Attrition of cage or pen mates during a study as cage or pen mates are removed from a study. 
  • During the process of separating pups by sex at the time of weaning, due to a lack of compatible cage mates.
  • Male rodents, due to their territorial nature, when used for breeding. Pregnant female mice may be singly or group housed during breeding paradigms.
  • Privately owned animals housed on campus for clinical studies or teaching activities may be housed individually or by household/source. Equids or cattle may be housed on pasture with other conspecifics with owner consent and appropriate oversight of introduction.

Rodents in DAR facilities that are housed individually should have cage cards identified using a color-coded sticker.  See the Guideline for more information.


Approved Date

Revised Date