The University of Iowa

Enrichment - Environmental Enrichment Program

Purpose: “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.” (The Guide for the Care and Use of Laboratory Animals, 8th ed.)  These guidelines will describe the University of Iowa’s Office of Animal Resource’s standard enrichment practices for each species listed.

In addition to the enrichment program details here, please see details of social housing located here.

Each rabbit is offered:

  • Vegetable (e.g. carrot, celery, etc.) weekly
  • Bio-Serv Bunny Block on a chain
  • One toy (e.g. Dumbbell, Jingle Ball or SS Rattle) at all times


image of a rabbit enrichment toy - jingle ball
  • Each rabbit is offered 2-3 small Shredded Wheat squares at each feeding
  • Other food enrichment items may be offered such as timothy cubes or hay


  • 1 Bio-Serv Rodent Retreat per cage


  • 1 Bio-Serv Ferret Ball per cage
    • For breeding animals, the Ferret Ball will be replaced with a nest box and bedding
  • 1 Bio-Serv Beefy Block on a Universal Hanging Chain per cage


  • One enrichment toy to be offered per cage at all times
  • Examples: Bio-Serv Big Red Apple, 12” Best Ball or Jingle Ball


Pig enrichment - Big red apple
pig enrichment - image of jingle ball
  • Milk jugs with food treats inside but must be removed from enclosure by end of day

Mice, Rats

  • Each mouse or rat is housed with enriched paper bedding
  • If any mouse or rat is not housed with enriched paper bedding, alternative enrichment is provided (e.g.  Nyla-bone, hut)



Guinea Pigs, Hamsters
Each guinea pig or hamster is housed with a retreat (e.g. Rodent Retreat Tunnel or Hut)


image of a rodent hut

Sheep and Goats

  • Sheep and goats are offered hay several times a week
  • A mirror may be used if animals are singly housed


  • Fish are offered brine shrimp daily


  • Pigeons are offered grit in addition to their regular diet
  • Additional enrichment is not routinely offered as it interferes with ongoing research


Last reviewed by the IACUC 11/8/2023