Office of Research Social Housing of Social Species - Office of Research

Social Housing of Social Species


The purpose of this document is to describe requirements for the social housing of social animals.


The 8th Edition of the ILAR Guide states: “Appropriate social interactions among members of the same species (conspecifics) are essential to normal development and wellbeing (Bayne et al., 1995; Hall 1998; Novak et al., 2006).  Single housing of social species should be the exception and justified based on experimental requirements or veterinary-related concerns about animal well-being. In these cases, it should be limited to the minimum period necessary, and where possible, visual, auditory, olfactory, and tactile contact with compatible conspecifics should be provided. The need for single housing should be reviewed on a regular basis by the IACUC and veterinarian.”

Both the Association for Accreditation and Assessment of Laboratory Animal Care (AAALAC) and the Office of Laboratory Animal Welfare (OLAW) have position statements supporting the concept of social housing as the default for social species.


For the purpose of this policy, social species include the following: nonhuman primates, dogs, cats (excluding intact males used for breeding), pigs (excluding boars), sheep, goats, cattle, horses (excluding stallions), alpacas, llamas, rabbits (excluding bucks and excluding does kept for less than 6 months), ferrets, rodents (excluding male mice used for breeding and female hamsters), marsupials (excluding monodelphis), chickens (excluding roosters), psittacines, quail, ducks, turkeys, fish, and songbirds. Social housing refers to housing animals in same sex, compatible pairs or groups in the animals’ primary enclosure.


Social housing will be considered the default method of housing for social animals. Single housing for experimental reasons must be described and justified in the IACUC protocol and approved by the IACUC. Each facility housing social animals must develop a Standard Operating Procedure (SOP) for social housing and include a description of the process for determining social incompatibility. Documentation for singly housed social animals must be available.


General Procedures:

  • Social animals will be housed in compatible pairs or groups, rather than individually, unless a single housing exemption has been approved in the relevant protocol or social housing poses an undue risk to the animals in question as determined by the facility manager and/or the area veterinarian. If the protocol-driven need for single housing is necessary only for a portion of the study, the animals should be socially housed before and after that time. The timeframe for single housing should be specified in the protocol.
  • Single housing of social animals post-operatively does not require a specific exemption approval in the relevant protocol. However, single housing must be for the minimum amount of time post-operatively necessary for recovery and/or healing as described in the animal care and use protocol.
  • Single housing for pre-anesthetic fasting does not require an exemption.
  • When social animals must be housed singly, conspecifics should be housed in visual, olfactory, and/or tactile range whenever possible.
  • When animals are left singly housed due to attrition of cage mates on study, or uneven experimental group sizes, consideration should be given to re-housing with other conspecifics when possible, depending upon the expected duration of the study. When re-pairing is not possible without disrupting the study, singly housing is acceptable for the remainder of the study.
  • When social animals must be housed singly, environmental and/or food enrichment, exercise/release into larger enclosures, and/or human interaction shall be provided unless scientifically contraindicated.
  • Husbandry staff, veterinary staff, and the IACUC are expected to monitor for single housing instances and ensure that single housing is approved in the relevant protocol.
  • This policy will be revised with the addition of new species to the census.


  • In many breeding arrangements pregnant females will be housed singly prior to birth. Female breeders may also have periods post weaning when they are singly housed prior to the next breeding. This does not need to be included in the IACUC protocol as an exemption as it is understood that this is a necessary part of maintaining a breeding colony.
  • If there are unbalanced litters (e.g., 4 females and 1 male) resulting in an animal not having an appropriate cage mate at weaning, attempts should be made to identify a cage mate. However if this is not possible, a note should be made in the animal’s record/cage card.
  • Facility SOP’s for colony management should describe the breeding program.

Procedure: IACUC-46
Date: October 20, 2016
Enabled by: OLAW, ILAR Guide
Supersedes: May 5, 2016