Housing Information

Cage Densities

Cage Densities for Mice being Housed in DLAR Facilities

Please refer to IACUC Policies, Procedures, and Guidelines Doc 110 “Housing Density”, on the Office of the Attending Veterinarian web site, in regards to housing space requirements for animals at the University of Kentucky.  To ensure that Investigators and Research staff observe The Guide and subsequently the IACUC expectations for mouse housing density, DLAR's Mouse Housing Density Policy explains how DLAR will handle overcrowding in a cage. 

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.



For questions concerning  a certain type of cage or cages used for breeding colonies, please contact via e-mail the DLAR Animal Care Supervisor where your animals are housed, our Facilities Operations Manager,  or any of the 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, University of Kentucky IACUC Policies, Procedures and Guidelines Doc 129 “Social Housing and Environmental Enrichment” along with 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.  DLAR will separate and or regroup incompatible animals as needed.  Individual housing may be requested if appropriate for the study, scientifically justified and approved in your animal use protocol.

A variety of suitable, species appropriate, enrichment items will be provided see Environmental Enrichment table below, items will be provided regardless of housing type unless specific instructions for your cohorts are received.  When requesting alternatives to micro-environment (within the housing unit) enrichment, including the withdrawal of enrichment, understand that this deviation MUST be indicated and listed in, scientifically justified,  and approved by the IACUC for the current approved animal use protocol.  A DLAR Service Request Form must be filled out and presented to the DLAR area Supervisor for where your animals are housed, 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 upon arrival, or from established groups already being housed in DLAR.   If you have questions regarding the DLAR Service Request form, please contact DLAR Area Supervisor.

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

New as of 29-Aug-2022:


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 Kongs®; 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


Hammocks; Container with Enviro-dri® bedding

PVC Pipes; Toys


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 biohazardous agents, 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.