Environmental Enrichment and Behavioral and Social Management of Research Animals


The Guide for the Care and Use of Laboratory Animals (the Guide, NRC 2011) states: "The primary aim of environmental enrichment is to enhance animal well-being by providing animals with sensory and motor stimulation, through structures and resources that facilitate the expression of species-typical behaviors and promote psychological well-being through physical exercise, manipulative activities, and cognitive challenges according to species-specific characteristics." (p. 52-53)

"Appropriate social interactions among members of the same species (conspecifics) are essential to normal development and wellbeing." (p. 64) "Single housing of social species should be the exception and justified based on experimental requirements or veterinary-related concerns about animal well-being." "In the absence of other animals, enrichment should be offered such as positive interaction with animal care staff and additional enrichment items or addition of a companion animal in the room or housing area."(p. 64)

IACUC Policy

The Institutional Animal Care and Use Committee requires that all animals be afforded at least one form of enrichment, and be housed in compatible groups. Exceptions to this policy are reviewed on a case-by-case basis with scientific justification.

IACUC Guidelines

Enrichment Items by Species

  Mouse Rat Guinea Pig Rabbit Dog Cat Pig Sheep Zebrafish

Nesting Material (8 oz.)

S E E S (pregnant) N/A N/A N/A N/A N/A
Social Housing S S S S S S S S S
Igloos/Huts/Tubes E S S N/A N/A N/A N/A N/A N/A
Forging Material E E E E N/A N/A E N/A N/A
Nylabone/chew toy E E E E N/A N/A N/A N/A N/A
Elevate platform E E E S S S N/A N/A N/A
Manipulanda (rotated) N/A E E S N/A N/A S S N/A
Radio N/A N/A N/A S S S S S N/A
Hay/Roughage N/A N/A S (daily) S (daily) N/A N/A N/A S (daily) N/A
Toys E E N/A N/A S (rotated) S (rotated) S (rotated) S N/A
Human Interaction N/A N/A E S S (daily) S (daily) S (daily) N/A N/A

Climbing apparatus (e.g. cat treet)

Nesting box     S (pregnant) S (pregnant) N/A N/A N/A N/A N/A
Exercise pen/area N/A N/A N/A S (no litters) S N/A N/A N/A N/A
Live feed (e.g. brine shrimp) N/A N/A N/A N/A N/A N/A N/A N/A


S= Standard Enrichment all animals receive unless scientifically justified in approved protocol

E= Extra enrichment which could be provided (outline below).

N/A- not applicable to species

1. Enrichment

a. Enrichment items are reviewed by the veterinarians prior to being placed into rotation for the animals.

i. Enrichment items should be rotated on a routine basis for large animals.

ii. All species should receive the standard enrichment items described above unless justified in the IACUC protocol.

iii. All enrichment items will be regularly inspected for safety and appropriately sanitized.

iv. Provision of extra enrichment should be based on the following circumstances:

1. Single housing (must be done)

2. Veterinary recommendation (e.g. stereotypic behavior, fighting, barbering)

3. Breeding concerns (must be documented)

2. Social housing

a. For most species social housing is the default unless justified in the protocol.

b. Certain instances may require single housing that is not described in the protocol:

i. Unbalanced sex ratios at weaning

ii. Male and female breeding animals

iii. Attrition during the course of a study

iv. Veterinary recommendation

c. If an animal is single housed due to scientific necessity or for a reason mentioned above, extra enrichment will be provided.

i. Extra enrichment will vary by species and can be one of the items listed in the table above as extra enrichment or an additional standard enrichment item.

Approved: October 2008

Revisions Approved 12/2012, 12/2015, 5/2018, 10/2020