{"id":2897,"date":"2017-08-07T07:55:07","date_gmt":"2017-08-07T07:55:07","guid":{"rendered":"https:\/\/az.research.umich.edu\/animalcare\/document\/environmental-enrichment-animals-sop\/"},"modified":"2026-01-22T09:54:23","modified_gmt":"2026-01-22T14:54:23","slug":"environmental-enrichment-animals-sop","status":"publish","type":"document","link":"https:\/\/az.research.umich.edu\/animalcare\/sops\/environmental-enrichment-animals-sop\/","title":{"rendered":"Environmental Enrichment for Animals SOP"},"template":"","categories":[5,6,7,8,9,10,11,12,13,14,15,16,17,18,19],"tags":[],"content-type":[30],"topic":[26],"update-type":[],"class_list":["post-2897","document","type-document","status-publish","hentry","category-cats","category-chickens-avian","category-cows","category-dogs","category-ferrets","category-fish-amphibians-and-reptiles","category-guinea-pigs","category-hamsters","category-mice","category-other-rodents","category-primates","category-rabbits","category-rats","category-sheep","category-swine","content-type-sops","topic-enrichment"],"acf":{"use_legacy_editor":true,"updated_date":"2025-12-12 00:00:00","update_notice":true,"author":"Unit for Laboratory Animal Medicine","summary":"This document outlines the use and approval of environmental enrichment<\/a> for all vertebrate animals.","button_links":null,"related_content":[3051,2898,2952,2928],"legacy_path":"environmental-enrichment-animals-sop","legacy_node_id":42,"legacy_related_nids":"1043, 43, 100, 74","legacy_content_section":[{"legacy_section_type":"heading","legacy_heading":"Responsibility","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area","legacy_heading":"","legacy_subheading":"","legacy_section_text":"
    \r\n \t
  1. Behavioral Welfare Group (BWG)<\/strong><\/li>\r\n \t
  2. ULAM Trainer\u00a0<\/strong><\/li>\r\n \t
  3. ULAM Husbandry Personnel<\/strong><\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"heading","legacy_heading":"Glossary Definitions","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"glossary_terms","legacy_heading":"","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":[2407,2683,2815,2686,2543,2575,2619,2691],"legacy_glossary_nids":"1074, 1364, 1591, 1367, 1214, 1247, 1295, 1372","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"heading","legacy_heading":"Procedures","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area_with_subheading","legacy_heading":"","legacy_subheading":"1. Animals That Receive Enrichment","legacy_section_text":"
      \r\n \t
    1. Provide vertebrate animals enrichment regardless of social housing status unless a SToP Form<\/a> is in place and it is justified in the AUP<\/a> or for animal health reasons.<\/li>\r\n \t
    2. Provide single housed animals with more than one enrichment item.\r\n
        \r\n \t
      1. Ensure additional enrichment item(s) are different from the first enrichment item, where possible.<\/li>\r\n \t
      2. Add additional enrichment at the first cage change from when the animal is noted to be single housed.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
      3. Limit the number of items given (i.e., offer only 2 items to a single housed animal; offer 1-2 items per animal for a pair of larger animals) to encourage novelty of environmental enrichment items and to alleviate resources.\r\n
          \r\n \t
        1. Consult the BWG<\/a> and the area faculty veterinarian to develop enrichment plans for large groups (>5 animals) of socially housed animals.\r\n
            \r\n \t
          1. Group housed sheep at the Sheep Research Farm do not necessarily require one item per animal as long as no negative interactions involving enrichment are observed.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
          2. Enrichment suggestions for various species include:\r\n
              \r\n \t
            1. Mice, gerbils, hamsters, voles:\r\n
                \r\n \t
              1. Provide at least one form of nesting material, where possible.<\/li>\r\n \t
              2. Provide voles with a:\r\n
                  \r\n \t
                1. Wooden chew toy in addition to one form of nesting material, where possible.<\/li>\r\n \t
                2. Mixture of sunflower seeds and corn in a small bowl.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                3. An additional enrichment item can be a different form of nesting material, e.g., if the mouse currently has a nestlet; envirodry or an enviropak could be added.<\/li>\r\n \t
                4. Refer to the AED<\/a>\u00a0for other secondary enrichment options.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                5. Rats and guinea pigs:\r\n
                    \r\n \t
                  1. Provide at least one hiding opportunity in the form of a shelter or shelf, where possible.<\/li>\r\n \t
                  2. An additional form of enrichment can be a different form of hiding opportunity, e.g., if the rat has a shelf, a tube or shelter could be added.<\/li>\r\n \t
                  3. Refer to the AED for other secondary enrichment options.<\/li>\r\n \t
                  4. Gnawing opportunities should be prioritized over nesting material.\r\n
                      \r\n \t
                    1. Nesting material can be provided as a secondary enrichment item to rats; however, nesting material is generally not considered as valuable for rats as it is for mice.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                    2. Rotate the additional enrichment item(s) for novelty on subsequent cage changes, where possible.<\/li>\r\n \t
                    3. African Grass Rats:\r\n
                        \r\n \t
                      1. Provide a handful of hay, where possible.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                      2. Rabbits and ferrets:\r\n
                          \r\n \t
                        1. Rotate the manipulanda enrichment items for novelty and to prevent boredom on subsequent cage changes, where possible.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                        2. Large animal species<\/a> :\r\n
                            \r\n \t
                          1. Rotate the enrichment items for novelty and to prevent boredom on subsequent cage changes, where possible.\r\n
                              \r\n \t
                            1. See Appendix A<\/strong><\/em> for a hanging quick guide on enrichment strategies involving animals single housed alone or with conspecifics in a room.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                            2. Non-human primates (NHP):\r\n
                                \r\n \t
                              1. Document provision of enrichment and produce\/food enrichment using in room logs. Utilize resources below to ensure consistent provision of the enrichment program.\r\n
                                  \r\n \t
                                1. Refer to the Non-Human Primate Husbandry SO<\/a>P.<\/li>\r\n \t
                                2. Refer to the Approved Enrichment Items \u2013 Non-Human Primate<\/a>s for enrichment options.<\/li>\r\n \t
                                3. See Appendix B for a quick guide which is posted in each NHP room and summarizes recommendations based on the animal\u2019s social housing status.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                4. Provide the following to all NHPs:\r\n
                                    \r\n \t
                                  1. TV and\/or sound machine.<\/li>\r\n \t
                                  2. A mechanism to better visualize the space outside the cage daily. Examples include:\r\n
                                      \r\n \t
                                    1. A porch<\/li>\r\n \t
                                    2. A mirror<\/li>\r\n \t
                                    3. Cage positioning in the room.<\/li>\r\n \t
                                    4. Other mechanisms approved by the veterinary personnel and investigative personnel.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                    5. For socially housed or paired NHPs:\r\n
                                        \r\n \t
                                      1. Provide 2 different manipulanda items per animal in the cage to be changed bi-weekly.<\/li>\r\n \t
                                      2. Provide a foraging device or opportunity with an approved food item once per week.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                      3. For singly housed NHP in a room with conspecifics:\r\n
                                          \r\n \t
                                        1. Provide 2 different manipulanda items.\r\n
                                            \r\n \t
                                          1. Change weekly or provide 2 additional manipulanda items on non-cage change weeks.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                          2. Provide a foraging device\/opportunity three times per week with an approved food item.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                          3. For singly housed NHP in a room without conspecifics:\r\n
                                              \r\n \t
                                            1. Provide 2 different manipulanda items.\r\n
                                                \r\n \t
                                              1. Change twice per week or provide additional manipulanda items on non-cage change weeks.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                              2. Provide a foraging device\/opportunity every weekday (M-F) except for major holidays.<\/li>\r\n \t
                                              3. Provide a large mirror facing the cage.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                              4. For NHPs categorized by federal regulations as having special considerations including singly housed NHPs in a room without conspecifics:\r\n
                                                  \r\n \t
                                                1. Veterinary personnel, the BWG, and investigative personnel develop a specific enrichment plan in addition to the implementation of the minimum enrichment program outlined above.<\/li>\r\n \t
                                                2. NHPs which have transient restricted movement by chairing do not require a specific enrichment plan unless the animal displays behaviors of psychological distress.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                3. The IACUC-approved animal care and use protocol is reviewed annually where research specific exemptions to the environmental enrichment plan for NHPs including social housing are scientifically justified.<\/li>\r\n \t
                                                4. A veterinarian and the BWG review non-scientific exemptions to the environmental enrichment plan for NHPs including social housing every 30 days and documents the review in the individual NHPs medical record.\r\n
                                                    \r\n \t
                                                  1. Permanent exemptions are recorded as such in the file and not reviewed every 30 days. Permanent exemptions include singly housed due to lack of suitable social partners due to attrition, incompatibility, etc.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                  2. Dogs: See the species-specific SOPs in the Related Documents<\/em> section<\/strong>.<\/li>\r\n \t
                                                  3. Zebrafish:\r\n
                                                      \r\n \t
                                                    1. Brine shrimp are the most common form of enrichment given to zebrafish.<\/li>\r\n \t
                                                    2. Prioritize visual access to other fish (i.e. fish in a neighboring tank), which can qualify as the secondary enrichment option for single housed zebrafish.<\/li>\r\n \t
                                                    3. Provide additional approved enrichment items for zebrafish without visual access to other fish.\r\n
                                                        \r\n \t
                                                      1. Refer to the AED for other secondary enrichment options.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                      2. Chickens:\r\n
                                                          \r\n \t
                                                        1. Provide an adequate amount of perching space\u00a0to ensure all chickens can roost comfortably.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                        2. Tree Shrews:\r\n
                                                            \r\n \t
                                                          1. Provide at least one hiding opportunity in the form of shelter.<\/li>\r\n \t
                                                          2. Provide at least one manipulanda piece of enrichment.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                          3. Zebra Finches:\r\n
                                                              \r\n \t
                                                            1. Provide an adequate amount of perching space to ensure all animals can roost comfortably but not so many that it interferes with flying.<\/li>\r\n \t
                                                            2. Provide at least one manipulanda piece of enrichment.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                            3. Aquatic frogs:\r\n
                                                                \r\n \t
                                                              1. X. laevis spp<\/em>\r\n
                                                                  \r\n \t
                                                                1. Provide:\r\n
                                                                    \r\n \t
                                                                  1. A plastic plant, or<\/li>\r\n \t
                                                                  2. PVC tube of appropriate size.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                  3. Hymenochirus\u00a0spp<\/em>\r\n
                                                                      \r\n \t
                                                                    1. Provide:\r\n
                                                                        \r\n \t
                                                                      1. Gravel or a photo of gravel under the tank<\/li>\r\n \t
                                                                      2. Plastic plant(s)<\/li>\r\n \t
                                                                      3. Plastic mouse huts\/igloos\/tents<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                      4. Leopard geckos:\r\n
                                                                          \r\n \t
                                                                        1. Ensure hot hut and cool\/moist hut are provided as outlined in the husbandry SOP.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area_with_subheading","legacy_heading":"","legacy_subheading":"2. Providing Enrichment","legacy_section_text":"
                                                                            \r\n \t
                                                                          1. Provide enrichment to vertebrate animals unless a SToP\u00a0Form<\/a> is in place stating otherwise.<\/li>\r\n \t
                                                                          2. Review enrichment options as described in the AED<\/a> and select an appropriate enrichment item based on species and individual animal size.<\/li>\r\n \t
                                                                          3. Position single housed large animals where each\u00a0animal can visually see the other, whenever possible.\r\n
                                                                              \r\n \t
                                                                            1. Report to the faculty veterinarian and social housing coordinator if adverse social behaviors or signs of distress are noted with this housing method.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                            2. Position a mirror for single housed large animas to visualize a reflection to mimic the presence of a conspecific when individually housed in a room.\r\n
                                                                                \r\n \t
                                                                              1. Mirror usage for animals does not take the place of providing other approved environmental enrichment items, except in zebrafish as stated in Procedures section 1.c.v.2<\/em>.<\/strong><\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                              2. Where applicable:\r\n
                                                                                  \r\n \t
                                                                                1. Ensure smaller items do not go down drains.<\/li>\r\n \t
                                                                                2. If item can be pushed out through the cage bars, do not use as sole enrichment item.<\/li>\r\n \t
                                                                                3. Remove any item that is broken or excessively worn; recover all broken pieces.<\/li>\r\n \t
                                                                                4. If hanging items are no longer hanging, locate and remove clip.<\/li>\r\n \t
                                                                                5. Watch for animals ingesting pieces of items.<\/li>\r\n \t
                                                                                6. Ensure chains used to hang items are no longer than three chain links (plus fasteners).\r\n
                                                                                    \r\n \t
                                                                                  1. Appropriately cover chains that are longer than three chain links.<\/li>\r\n \t
                                                                                  2. Exception: tree shrews may have uncovered chains or zip ties at the discretion of the faculty veterinarian.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                                  3. Change enrichment items at regular intervals or as required per AED; and\u00a0rotate items to maintain novelty of the items\u00a0and prevent boredom\u00a0when possible.\r\n
                                                                                      \r\n \t
                                                                                    1. Replace, sanitize, or transfer enrichment at cage change as appropriate for all species. The type of enrichment does not need to be recorded on Room Sheet (e.g., Animal Room Log Sheet) except for NHPs.\r\n
                                                                                        \r\n \t
                                                                                      1. Record NHP enrichment on the Nonhuman Primate Enrichment and Husbandry Log. See Non-Human Primate Husbandry SOP<\/a>, Appendix B<\/strong>.<\/em><\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area_with_subheading","legacy_heading":"","legacy_subheading":"3. Approval of New Enrichment Items","legacy_section_text":"
                                                                                          \r\n \t
                                                                                        1. The Behavioral Welfare Group (BWG) approves all enrichment items not found in the AED prior to implementation.\r\n
                                                                                            \r\n \t
                                                                                          1. Submit new enrichment ideas or examples to the Behavioral Welfare Group: Request for Approval of New Enrichment Item. Provide the following information:\r\n
                                                                                              \r\n \t
                                                                                            1. Costs for each item (purchase price or labor to construct).<\/li>\r\n \t
                                                                                            2. How labor intensive the enrichment is projected to be.<\/li>\r\n \t
                                                                                            3. Novelty of enrichment item.<\/li>\r\n \t
                                                                                            4. Proposed schedule of applying and rotating enrichment.<\/li>\r\n \t
                                                                                            5. Item disinfection requirements.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                                            6. The BWG evaluates each item and enters all relevant information into the AED whether approved or denied for use. Include the following information in the AED:\r\n
                                                                                                \r\n \t
                                                                                              1. Approved items:\r\n
                                                                                                  \r\n \t
                                                                                                1. Item name<\/li>\r\n \t
                                                                                                2. Item description<\/li>\r\n \t
                                                                                                3. Approved species use<\/li>\r\n \t
                                                                                                4. Approved disinfection procedures (if applicable)<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                                                5. Denied items:\r\n
                                                                                                    \r\n \t
                                                                                                  1. Name<\/li>\r\n \t
                                                                                                  2. Reason for denial<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                                                                                  3. The BWG can approve items on a trial basis with PI consent.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area_with_subheading","legacy_heading":"","legacy_subheading":"4. Training","legacy_section_text":"
                                                                                                      \r\n \t
                                                                                                    1. Trainers or husbandry supervisors ensure training of all relevant enrichment items in the area for husbandry technicians prior to employing use of any items.<\/li>\r\n \t
                                                                                                    2. Training can be done by providing:\r\n
                                                                                                        \r\n \t
                                                                                                      1. Detailed descriptions of item applications via the AED.<\/li>\r\n \t
                                                                                                      2. Hands-on demonstrations for any items that:\r\n
                                                                                                          \r\n \t
                                                                                                        1. Involve safety concerns for humans or animals (i.e., NHP enrichment).<\/li>\r\n \t
                                                                                                        2. Are not routinely used.<\/li>\r\n \t
                                                                                                        3. Involve direct handling of the animals (i.e., hand walking canines).<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"text_area_with_subheading","legacy_heading":"","legacy_subheading":"5. Cleaning \/ Sanitizing Enrichment Items","legacy_section_text":"
                                                                                                            \r\n \t
                                                                                                          1. Clean, disinfect<\/a>, sanitize, or discard items in accordance with the information in the AED<\/a>.<\/li>\r\n \t
                                                                                                          2. Transfer certified wood enrichment items with animals at cage change if not soiled, splintered or brittle.\r\n
                                                                                                              \r\n \t
                                                                                                            1. Discard soiled, splintered or brittle wood enrichment and replace as needed.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"heading","legacy_heading":"Appendix A: Large Animal Standard Enrichment Room Poster","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"","legacy_media_file":"","legacy_media_url":"","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"link_button","legacy_heading":"","legacy_subheading":"","legacy_section_text":"","legacy_media_position":"media-full","legacy_media_file":3113,"legacy_media_url":"https:\/\/az.research.umich.edu\/sites\/default\/files\/media\/embedded\/Appendix%20A_Large%20Animal%20Standard%20Enrichment.pdf","legacy_glossary_term":"","legacy_glossary_nids":"","legacy_resource":"","legacy_resource_nids":"","legacy_buttons":[{"legacy_button":{"title":"Large Animal Standard Enrichment Room Poster","url":"https:\/\/az.research.umich.edu\/animalcare\/wp-content\/uploads\/sites\/2\/2025\/01\/Appendix-A_Large-Animal-Standard-Enrichment.pdf","target":""},"legacy_import_link":true}]},{"legacy_section_type":"heading","legacy_heading":"Appendix B: Nonhuman Primate Minimum Enrichment Room Poster","legacy_subheading":"","legacy_section_text":"","legacy_media_position":false,"legacy_media_file":null,"legacy_media_url":"","legacy_glossary_term":null,"legacy_glossary_nids":"","legacy_resource":null,"legacy_resource_nids":"","legacy_buttons":null},{"legacy_section_type":"link_button","legacy_heading":"","legacy_subheading":"","legacy_section_text":"","legacy_media_position":false,"legacy_media_file":null,"legacy_media_url":"","legacy_glossary_term":null,"legacy_glossary_nids":"","legacy_resource":null,"legacy_resource_nids":"","legacy_buttons":[{"legacy_button":{"title":"Appendix B: Nonhuman Primate Minimum Enrichment Room Poster","url":"https:\/\/az.research.umich.edu\/animalcare\/wp-content\/uploads\/sites\/2\/2025\/01\/NHP-Minimum-Enrichment-Room-Poster.pdf","target":""},"legacy_import_link":true}]}],"update_notice_type":[51,52],"update_notice_start":"2026-01-12 21:00:00","update_notice_end":"2026-04-13 21:00:00","update_notice_text_blocks":[{"update_notice_text":"

                                                                                                              Summary of Changes<\/strong><\/span><\/h3>\r\n