Pet Mouse Care Sheet: Habitat, Diet, and Behavior

Mice are social, inquisitive rodents that make excellent companions for beginner pet parents.

Mice are smaller than rats, gerbils, and some species of hamsters, with the average mouse’s body measuring around 3 inches long (not including its tail). 

Mice are so small that they can squeeze through very tight spaces. If using a wire cage, ensure the wires are spaced no further than ¼-inch apart to prevent escape. 

Mice tend to be nocturnal or crepuscular (active around dawn and dusk), but they may adjust to their pet parent’s schedule over time.

Pet Mouse Supplies Checklist

To keep a mouse happy and healthy, pet parents should have these basic supplies on hand: 

• Appropriately sized habitat (at least 20” L x 10” W x 12” H) 

• High-quality pelleted mouse food

• Treats 

• Bedding 

• Nesting material 

• Food bowl/water bottle 

• Exercise wheel 

• Hideaway place 

• Toys 

• Wood chews 

• Chew tubes 

Mouse Habitat

Choosing the Right Enclosure 

A single mouse’s habitat should measure at least 20” L x 10” W x 12” H.

Enclosures should be well-ventilated and secured with an escape-proof lid. Enclosures with horizontal bars and multiple levels are ideal since mice love to climb and explore.

It’s always good to provide your mouse with the largest habitat possible.

Wire habitats offer the best ventilation and are easy to clean. However, pet parents should keep in mind that tiny mice can escape the enclosure if the bars aren’t spaced closely enough.

If a wire cage is used, the habitat should have a solid base, and the spaces between the cage’s bars should be around ¼-in apart or smaller to prevent the mouse from escaping or getting stuck.  

Glass and plastic habitats are not recommended, as their solid walls block air circulation.

Mice have sensitive respiratory tracts, and habitats with solid walls can trap ammonia fumes from droppings more quickly, putting mice at greater risk for infection. 

Setting Up Your Habitat 

Mice are comfortable in average household temperatures, no higher than 80 F.

Mice enclosures should be kept in a quiet, draft-free area that’s not close to an air conditioner or accessible to other pets, like cats and dogs. Habitats should never be kept in direct sunlight. 

Female mice can typically be kept in pairs or small groups if they have adequate space in their enclosure. Otherwise, adult mice should not be housed in the same enclosure.

Mice start breeding at 6–8 weeks of age, so males and females should not be kept in the same enclosure unless the male is neutered, or the female is spayed. 

Mice kept in the same habitat should be monitored for aggressive behavior. If two mice fight, separate them. Never keep different species of animals in the same habitat.  

Bedding for Mice

Pet parents should have two types of bedding in their mouse’s habitat: an absorbent substrate to line the bottom of their enclosure, and a nesting material that they can use to make a cozy burrow. 

1 to 2 inches of high-quality, paper-based bedding or crumpled paper should be added to the bottom of the habitat. Paper-based bedding should be used instead of wood shavings or chips of any kind. Unlike wood, paper is low-dust and digestible, meaning it won’t obstruct a mouse’s gastrointestinal tract if ingested. 

Avoid cedar-based and pine bedding products. These products have aromatic oils that can irritate a mouse’s skin and sensitive respiratory tract. 

Natural-born burrowers, mice enjoy building nests out of shredded paper, hay, and straw. Adding a generous layer of nesting material to a mouse’s enclosure can help them satisfy their desire to build nests and hide food. 

Décor and Accessories for Mouse Enclosures

Every mouse needs at least one hiding space in their habitat for privacy. Hideout boxes made from chewable materials like hay or wood make excellent choices.  

Plastic hideouts, like the Kaytee Small Animal Igloo Hideout, are durable and easier to disinfect, but they should be removed from the mouse’s enclosure if your pet begins to chew on it.

The broken plastic pieces can obstruct a mouse’s gastrointestinal tract if ingested and cause serious injuries. 

Daily exercise is vital to a mouse’s overall health. A running wheel is a convenient way to satisfy a mouse's instinctual need to run. 

Ensure that the wheel’s running surface is smooth and won’t entrap a mouse's feet or toes, causing injury.

A mouse’s front (incisor) teeth grow continuously, so a variety of mice-safe chew toys should be added to their enclosure to help them wear down these teeth gradually.

Toys also keep mice busy and allow them to enjoy physical activity, which helps prevent obesity and other health issues. 

Climbing ladders, cardboard or PVC tubes, and branches all make excellent additions to a mouse’s habitat.

Cleaning and Maintenance

Pet parents should spot-clean their mouse’s bedding daily, removing any soiled material and uneaten food. The entire habitat and its contents should be cleaned thoroughly at least once a week. 

To clean a mouse's habitat, take these steps: 

1. Move the mouse to a pet-safe temporary enclosure and remove any old bedding or litter from the habitat. 

2. Use a small animal habitat cleaner or 3% bleach solution to wash the habitat and any accessories.

   • The bleach solution should stay on the habitat for at least 10 minutes to ensure that the surfaces are properly disinfected. If using a commercial habitat cleaner, like Nature's Miracle Small Animal Cage Cleaner, follow the manufacturer's instructions. 

3. Rinse the habitat and accessories thoroughly with water, making sure to remove any trace amounts or residual smells of the cleaning agent or bleach solution. 

4. Allow the habitat and its contents to dry completely before placing new bedding, clean accessories, and the mouse back into the habitat. 

5. Return the mouse to the clean habitat. 

Other Accessories 

A small animal playpen can supply a safe, spacious area for mice to play and exercise outside of their enclosed habitat–which is ideal for enrichment.

Mice are excellent climbers and notorious escape artists, so pet parents should always supervise their mice while they’re outside their usual habitat. 

What Do Mice Eat?

Mice enjoy a diet of high-quality rodent lab blocks or pelleted food, as well as limited amounts of grains, vegetables, fruits, hay, and treats.

Since mice like to graze, they should always have access to fresh food and clean water. 

A nutritious and well-balanced mouse diet consists of high-quality rodent lab blocks or pelleted food that’s formulated especially for mice. Mice should be fed daily, preferably in the evening. 

Grains, vegetables, fruits, hay, and treats, offered in limited quantities (no more than 10% of the mouse's daily diet).

Most fruits are mouse-safe, but mice should not eat fruit seeds or pits, citrus fruits, or rhubarb. 

Fruits and vegetables should always be cut into small, bite-sized pieces before serving. Because fruits are naturally high in carbohydrates, excess fruits in a mouse ‘s diet can upset their gastrointestinal tract and may cause obesity.   

Do not offer mice garlic, onions, unripe tomatoes, raw beans, or potatoes.  

Water should be changed daily and offered in a shallow, chew-resistant bowl or water bottle.

Pet parents should regularly clean and disinfect their little one’s water bowl or bottle to prevent bacteria from forming.  

Bowls should not be too deep, as the mouse may slip inside and get trapped.  Make sure that the bowl is sturdy enough to not be knocked over by an excited mouse. 

Do not allow mice to consume chocolate, caffeine, or alcohol, because these are toxic and can cause death or serious illness.

Sugar and high-fat treats should also be avoided because they can cause digestive upset. 

Pet parents should discard any uneaten fruits and vegetables after 10 hours, as they may spoil and cause infection if eaten.

Mouse Behavior and Socialization

Mice can be skittish and excitable until they are properly socialized and acclimated to their environment. With gentle daily handling, they become docile pets and can even learn tricks! 

Patience is key when handling mice. Allow newly homed mice a few days to adjust to their environment before trying to handle them.  

Never grab a mouse by their tail or squeeze their body. Mice are excellent at jumping and should be handled over a soft or padded surface to prevent injury if they fall. Children of any age should be supervised by an adult while handling a mouse. 

Always wash your hands before and after handling your mouse or the habitat’s contents. All small animals are potential carriers of infectious diseases, such as rat bite fever and Salmonella bacteria, which are zoonotic (transmittable to humans).

Mice are typically not compatible with other household pets including other rodents, cats, and dogs, and will generally do best when housed singly, although occasionally two to three females can be housed together.

Often, however, group housed mice will fight or show signs of stress and need to be separated. 

Most mice are crepuscular to nocturnal, meaning that they will be active at dawn and dusk, as well as often during the night—which can mean that they disrupt the sleeping habits of their humans.

Mouse Grooming

Mice are clean animals that groom themselves regularly and rarely need baths, but pet parents can spot-clean them by using a damp washcloth or unscented baby wipes, as needed.  

Hair loss, decreased appetite, weight loss, lethargy, sunken eyes, and loose stools can all be signs of underlying health issues. Pet parents should consult with a veterinarian if they see any of these symptoms or other changes in mood, behavior, or appearance. 

Most mice will not need to have their nails trimmed, as their nails wear down with daily use.

If a mouse’s nails begin to curl, or if they start leaving scratches on themselves during self-grooming, they should be taken to a veterinarian for trimming.  

The front (incisor) teeth of mice grow continuously, so pet parents should give them safe wooden toys or other chewable items to encourage gnawing.

Mice teeth turn orange yellow color as they age. This is completely normal not a sign of poor hygiene. 

Consult a veterinarian if a mouse's teeth seem too long, if they are drooling excessively, or if they are dropping food when they eat. 

Mouse Veterinary Care

Annual Care

Mice should be examined by a veterinarian a few times a year. When transporting mice in a travel carrier be sure that the gaps between bars are small enough that your mice can’t escape and that the material is resistant to being chewed.

Never transport mice in cardboard carriers.

Bring food and water in the carrier. It is also helpful to bring pictures of your mouse’s enclosure and all supplies.

Signs of a Healthy Mouse

• Clear eyes

• Clean nose

• Clean ears

• Shiny hair coat

• Clean feet

• Nails and teeth that are not overgrown

When to Call Your Vet

• Weight loss

• Wounds or trauma

• Excessive scratching

• Lumps

• Coughing, wheezing, sneezing, nasal discharge, or other respiratory difficulties

• Diarrhea

• Anorexia

• Drooling

• Overgrown teeth

Common Illnesses in Mice

• Obesity

• Ectoparasites (lice, fleas, mites, etc.)

• Alopecic (hair loss) conditions

• Stress related conditions

• Respiratory infections

• Tumors

• Trauma, especially bite wounds

• Heat stress/heat stroke

• Malnutrition

• Dental disease/malocclusion

• Toxicities/poisonings

• GI pathogens (giardia, salmonella)

• Bumblefoot