In compliance with the Animal Welfare Act, Animal Welfare Regulations, and the 2011 Guide for the Care and Use of Laboratory Animals:
The default method of housing social animals (rodents, dogs, nonhuman primates, etc.) is with at least one other conspecific.
Exceptions to this must be scientifically justified in an Institutional Animal Care and Use Committee (IACUC)-approved protocol, or based on veterinary-related concerns.
Appropriate environmental enrichment must be provided in laboratory animal housing unless there is scientific justification, approved by an Animal Care and Use Committee, that precludes the use of enrichment materials or practices.
All animal housing facilities must have a program of environmental enrichment for all species maintained in that facility. Social housing only, for most species, does not provide adequate environmental enrichment.
The attending veterinarian and the Animal Care and Use Committee must review and approve this program regularly.