Office of Research Integrity

Social Housing Policy

All social animals must be pair/group housed when possible1,2.

  • Single housing of animals immediately post-operatively does not constitute an exception. The veterinarian will decide when animals can be pair housed after recovery from surgery.
  • Planned exceptions must be described and scientifically justified in the protocol. Examples of research-related exceptions may include viral or antibody status; requirement for continuous monitoring or sample collection; special instrumentation; or requirements related to behavioral studies. If approved, such exemptions will be valid one year, and must be addressed during the annual review of the protocol.
  • Exceptions may also be based on veterinarian-approved medical exemptions.
  • Exceptions which become necessary as a result of unexpected research-related events or veterinarian-approved medical exemptions expected to be chronic must be submitted as an amendment to the protocol.
  • Lack of suitable social partners may prevent pair/group housing. When suitable partners are not available, increased manipulanda/toys and other forms of enrichment will be provided on a species-appropriate basis (e.g., a mirror placed in front of the cage/pen, daily positive social interactions with animal care staff).
  • Veterinarian 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. Future grouping attempts with new partners may be tried at the discretion of the veterinarian when new animals enter the facility. Single housing at the recommendation of the veterinarians does not constitute an exception which must be described and justified in the protocol, as long as the problem is isolated. If social incompatibility is a trait of a specific strain or specific groups within the strain (i.e., all males), the need for single housing must be described and justified in the protocol.

New orders will request that vendors supply compatible pairs/groups when available.

Considerations for determining the suitability of grouping partners include:

  • Health status of proposed cagemates, including viral status or inoculation history and any behavioral issues/observations
  • Current protocol and any research related concerns
  • Physical attributes – age, weight, sex of the animal
  • History of social/individual housing

Addition of any new specialized species will initiate review of species-specific enrichment opportunities at the time of animal care Standard Operating Procedure (SOP) development. (1/13)


1. Institute for Laboratory Animal Research. Guide for the Care and Use of Laboratory Animals 8th edn. (National Academies Press, Washington, DC, 2011).
2. Animal Welfare Act and Animal Welfare Regulations. 9 CFR Ch.1 §3.