Housing Information

Cage Densities

Cage Densities for Mice being Housed in DLAR Facilities

Please refer to IACUC Guidelines and Standard Operating Procedures - 110 Mouse Housing Density. This document is available on the IACUC Policies and Guidelines page through the Office of the Attending Vet. 

Below are examples of the different types of mouse housing caging used in the DLAR facilities, including the number of adult animals that can be housed in each type of caging. 

Micro Isolator Cage

Standard Static Micro Isolator Cage 
This cage holds 4 adult mice, and are most often used on shelf racks.



Small Tecniplast PIV Cage

Small Tecniplast PIV Cage
This cage holds 4 adult mice. 
There are 144 of these cages per rack.



Large Tecniplast PIV Cage

Large Tecniplast PIV Cage
This cage holds 5 adult mice. 
There are 112 cages of this type on a rack.



Green Line Tecniplast PIV cage

"Green Line" Tecniplast PIV Cage
This cage holds 5 adult mice.



2 Redline Allentown Cages

"Redline" Allentown Cage
This cage holds 5 adult mice.



If you have a breeding colony, please check with the Supervisor, our Facility Manager, our Training Coordinator or any of our DLAR Veterinarians for specifics regarding the requirements for breeding cages.  If you have questions concerning  a certain type of cage, please contact the Supervisor of the area where your animals are housed, our Facility Manager,  or any of our DLAR veterinarians.

social housing

Social/Group Housing and Enrichment

Following the recommendations outlined in the 8th Edition of the ILAR Guide for the Care and Use of Laboratory Animals, and other regulatory and accrediting bodies, group housing of social mammalian species and enrichment of these animals is the default for the Division of Laboratory Animal Resources.

A variety of suitable, species appropriate, enrichment items will be provided. We will separate or regroup incompatible animals if needed. You may request individual housing if appropriate to your study. Enrichment items will be provided regardless of housing type unless specific instructions for your cohorts are received.  If you request single housing or alternatives to micro-environment (within the housing unit) enrichment, including the withdrawal of enrichment, please understand that this deviation MUST be indicated and  listed in, scientifically justified,  and approved by the IACUC in your current approved animal use protocol.  A Special request form must be filled out and presented to the DLAR staff indicating which caging this deviation involves, the length of time it will be in effect, and current contact information for your staff responsible for the group of animals involved. This information must be provided whether it is individual housing of animals on arrival, or from established groups already being housed in DLAR, withholding or limiting the enrichment items, and the dates the Special Request is to begin. If you have questions regarding this policy, please contact DLAR.

Additional items may be added as available or appropriate.  Environmental Enrichment Table (PDF 1 pg.)


Default Enrichment

Optional Enrichment




Minimum two toys in cage, produce fed daily, playpen access (if playpens are available) on a rotational basis within cage quadrant; daily human interaction

Destructible toys, such as chew sticks, mirrors, food/foraging, swimming pool, swing


Stainless Steel Mirror; forage feeder; Hay bags w/ timothy grass

Hanging apple, milk jug toy, Pleasant Sheep Sounds









Rubber or plastic balls, heavy chains,

empty plastic milk jugs, Forage feeders

Assorted fresh fruit and

vegetables, candy bars, and Milk Bone

Dog Biscuits® offered on occasion, Brooms fixed to side of cage for scratching

Ointment to apply to dry skin with human interaction

Pool to place items to root with (shavings; toys)


Toys, Nylabones®, raised beds, indoor and outdoor playrooms

Starch Bones

Playground climbing equipment



Timothy cubes, assorted fresh greens and fruit, Bunny Blocks™ in various flavors, Veggie Bites™, commercial rabbit treats

Toys such as a jingle ball, Steel hanging items (washers), empty plastic bottles

Guinea pig

Sterilized paper tubes, Polycarbonate

Guinea Pig Huts® and Rodent Retreats

Commercial Guinea Pig treats,

apples, and carrots



Sterilized paper tubes and tissues, Rodent Retreats®, Crawl Balls®





Enviro-dri® bedding

Sterilized paper tubes and tissues, Rodent Retreats®,Nylabone®, Crawl Balls®; Aspen Chew Sticks; Foraging Items





Nestlets®,  Enviro-dri® bedding

Sterilized paper tubes or

tissues, Shepherd Shacks® , Mouse Igloos® with or without Fast Tracs®, Nest Puck, Aspen Chew Sticks, Foraging Items


Mouse, nude or hairless



Enviro-dri® bedding

Sterilized paper tubes or

tissues, Shepherd Shacks® , Mouse Igloos® with or without Fast Tracs®, and mouse houses

Spiny Mouse


Assorted PVC pipes

Nylabone®, Mouse Igloos®

Carrots, Sunflower seeds



Group housed on pasture, Human interaction

Mazuri Alpaca Pellets


Artificial Turf Resting Pad

Flight Cage Access

Warm Water Bath Access



Resting Pad

Dust Baths, Meal worms, Fruit

barrier housing

Clarification on What Is and Is Not Barrier Housing

Rodent barrier housing is NOT the normal housing condition in DLAR. Barrier housing refers to

  1. immunocompromised or other animals where maintaining environmental sterility is critical and
  2. animals infected with biohazardous agent (ABSL2 & 3) where agent inactivation is critical.

In the former case the goal is protection and the feed, water, caging, and bedding is sterile either through being purchased as sterile (irradiated) or autoclaving. In the case of biohazardousagents, the caging and contents are subjected to autoclaving after animal housing to destroy the biohazardous agents.  In both cases, the caging is subjected to sterilization procedures which require additional labor, equipment, and shortens caging life expectancy.  

The routine housing of mice and rats in individually ventilated caging (IVC’s) or microisolators is NOT barrier housing. These caging systems are used to minimize disease transmission between caging and to reduce allergen exposures.