As laboratory animals spend the large majority of their lives in their home enclosure, the design of this area is critical for their health and welfare. Substandard housing can lead to aggression, stereotypes, and anxiety. The best housing should promote key species-specific natural behavior and allow animal choice.

Making changes to current housing standards can be challenging especially because of variations between cabin styles. Work from where you are at for continuous improvements. Also keep in mind that some of the recommendations below (e.g., providing running wheels to mice) can impact some specific experimental models.

Before implementing housing changes, be sure to consult the relevant scientific literature and consider the requirements of your scientific model. Each facility may require an individual approach to increasing housing standards. We recommend considering these implementation tips.

A mouse peeks out of a well-formed nest.
Mice

Key Natural Behaviors

  • Social structure
  • Nesting
  • Burrowing
  • Climbing
  • Foraging
  • Nocturnal/crepuscular
  • Avoid open spaces

Recommendations

  • Stable group housing
  • Water/food at one end
  • Nesting material - minimum of 8 grams for 3-5 mice. (Transfer clean & dry nesting material during cage change.)
  • Aspen bedding is generally preferable compared to corn cob
  • Tubes & climbing structures
  • Avoid cages being in the direct path of ultrasound when possible (dripping taps, cart wheels, computers)
  • If using individually ventilated cages, monitor for anxiety/discomfort based on high air change rate
  • Running wheels
  • Gnawing sticks
  • Avoid bright light (mice prefer <65 lux) especially covering the top row of cages on a rack
  • Grid space, mouse lofts, or mezzanines
  • Tunnel handling or cupping: see our Rodent Handling page for tips

Video Procedure Guide

Further Reading

A highly enriched group housed rat cage.
Rats

Key Natural Behaviors

  • Highly social
  • Burrowing
  • Climbing
  • Foraging
  • Nocturnal/crepuscular
  • Avoids open spaces

Recommendations

  • Stable social groups
  • Cages that are large & tall enough to allow rats to stand upright, stretch, and climb
  • Solid floors
  • Avoid brightly lit home enclosures
  • Positive handling such as tickling when juveniles
  • Nesting material, shelters, tubes/climbing structures
  • Aspen bedding is generally preferable compared to corn cob
  • Gnawing materials such as wood blocks or chew sticks
  • Access to digging materials such as deep shaving, dirt, crinkle paper, etc.
  • Playpens or exercise areas with water trays, running wheel, ladders, ropes, etc.
  • Rat tickling and low-stress handling: see our Rodent Handling page for tips

Video Procedure Guide

Further Reading

Semi-naturalistic housing
Semi-naturalistic housing
More traditional rat housing with limited enrichment

*Dr. Melanie L. Graham, Preclinical Research Center, Department of Surgery, University of Minnesota, Twin Cities Campus.

If you know of other rodent housing resources that you think should be featured on this page, please contact us at contactus@na3rsc.org.