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Mouse Care Sheet

Developed with and approved by a qualified veterinarian.



Mus musculus

Mice are social, alert and extremely active small animals. They may be skittish at first, but with daily gentle handling they can become docile and sweet companions.

Table of Contents

Typical appearance and behavior  

  • Are smaller than ratsgerbils and some hamsters
  • Fur comes in a variety of colors, including white, gray and brown 
  • Have long hairless tails and round ears 
  • Are social animals who enjoy living with other mice 
  • Pairs or small groups of females typically live well together as long as they have enough space 
  • Males generally do not do well living together unless they are littermates and have been together from the start 
  • Do not house males and females together unless you want many baby mice. They will start breeding at 6 to 8 weeks of age 
  • Are so tiny that they can squeeze into and through very tight spaces 
  • Play during the night and rest during the day (nocturnal) but can adjust to pet parents’ schedules 
  • Can become obese if not given exercise opportunities inside and in an escape-proof location outside their habitat 
  • Very curious and like to burrow, hide in objects and play; easily frightened by loud noises 
  • Will learn to recognize the sight and sounds of their pet parents 
  • Chew on wooden objects to wear down their continuously growing incisor teeth  
  • Are great at jumping, so should be held in the palm of a hand and never grabbed by the tail to transport 
  • Should always be held over a soft surface so they don’t injure themselves if they jump or fall 
  • Can be trained to sit in a hand or on a shoulder by repeatedly feeding them treats when they are sitting there 
  • Like to build nests out of shredded paper and straw 
  • Can be good pets for families with older children who can participate in the care and handling of mice with supervision 



Care Difficulty Beginner
Average Life Span up to 3 years with proper care
Average Adult Size 3 inches long, not including tail
Diet omnivore
Minimum Habitat Size 20" L X 10" W X 12" H tank or wire mesh cage for up to four mice; narrow bar spacing


Habitat size

Provide the largest habitat possible so the mouse can hide, burrow, exercise and play. Metal, wire-based habitats have better ventilation, but bar spacing must be narrow enough to prevent tiny mice from slipping through. Glass or plastic habitats may be used but are harder to keep ventilated; bedding in tanks may require more frequent changing to prevent ammonia smell from droppings. Horizontal bars and multiple levels are ideal, as mice love to climb. Habitats should have solid floors to prevent toes and feet from getting caught. All habitats should have a securely attached top to prevent escape.

Building your habitat

  • Mice acclimate well to average household temperatures, not to exceed 80°F; be cautious of extreme temperature changes. The habitat should never be in direct sunlight or in a drafty area and should be inaccessible to other pets, such as curious cats and dogs. 
  • Bedding - Use 1 to 2 inches of high-quality, commercially available paper-based bedding or crumbled paper. Paper-based bedding is preferred over wood shavings of any kind because it is digestible if mice eat it and less dusty (so less prone to irritate mice’s respiratory tracts); wood shavings can cause gastrointestinal (GI) tract obstruction if ingested. Nesting material provides additional enrichment, allowing mice to bury themselves and build nests.  
  • Hideaways  -Many mice enjoy a hiding place within their habitats. Commercially available wood- and hay-based habitats are available for them to hide in and chew on; hard plastic hideaways are easy to disinfect but should be removed if mice chew on them to prevent ingestion of plastic pieces 
  • Wheels - Provide an appropriately sized running wheel for exercise; be sure the wheel has a smooth running surface to prevent mice from catching and injuring toes and feet 
  • Toys and chews -  
    • Mice love to run through cardboard or PVC tubes and climb ladders 
    • Must be provided with appropriately sized wooden blocks to chew on

Cleaning your habitat 

  • Spot-clean the habitat and remove soiled bedding and discarded food daily. At least once a week, thoroughly clean and disinfect the habitat and its contents: 
    • Replace all bedding and wash all habitat contents with a small animal habitat cleaner or 3% bleach solution 
    • Rinse off habitat cleaner or bleach residue thoroughly  
    • Allow the habitat and décor to dry completely before returning your mouse to the habitat 

What Do Mice Eat

A well-balanced mouse diet consists of: 

  • High-quality rodent lab blocks or other commercially available, nutritionally complete pelleted food for mice and limited amounts of grains, vegetables, fruits and Timothy or other grass hay 
  • Pellets and other foods should be fed in separate dishes 
  • Vegetables and fruits should be offered in tiny, bite-size pieces 
  • Clean, fresh water, changed daily, in a sipper bottle or a shallow bowl  
  • Bowls should not be too deep as to allow mice to fall into them and get stuck  
  • Sipper bottles should be checked regularly to ensure water flow is unobstructed 
  • Do not feed chocolate, caffeine or alcohol as these are toxic to mice and can cause illness or death; avoid salty, sugar and fatty treats 

Things to remember when feeding your mouse: 

  • Always have fresh food and water available since mice like to graze 
  • Feed once a day in the evening; mice are generally more active at night, so you may want to replenish food then 
  • You can give small amounts of grains, vegetables, fruits and hay daily, but limit these to 10% of your mouse’s total daily calories 
  • Vegetables and fruits not eaten within 12 hours should be discarded 

Common mouse health issues

Health Issue Symptoms or Causes Suggested Action
Health Issue Diarrhea Symptoms or Causes Loose stool; can be caused by poor diet, stress, GI parasites, bacterial or viral infection, unclean housing or other illness. Suggested Action Consult with a veterinarian to determine cause and treatment.
Health Issue Dental problems Symptoms or Causes Overgrown teeth, difficulty chewing, drooling, swelling of jaw, weight loss. Suggested Action Consult with a veterinarian to have teeth trimmed regularly.
Health Issue Skin infection Symptoms or Causes Hair loss and/or dry, flaky, itchy skin; can be caused by external parasites (such as mites), fungal infection (ringworm) or bacterial dermatitis. Suggested Action Consult a veterinarian for treatment; ringworm and some species of mites are contagious to people.
Health Issue Tumors Symptoms or Causes Abnormal lumps or swellings with or without lethargy, decreased appetite, weight loss. Suggested Action Consult a veterinarian.


  • How long do pet mice live? Up to 3 years with proper care and nutrition. 
  • What do pet mice eat? Commercially available rodent blocks or pelleted diets along with smaller amounts of grains, fresh vegetables and fruits, and hay, plush fresh water daily. 
  • How do you take care of a mouse? Provide an appropriately sized, escape-proof glass or wire mesh cage with a solid floor and securely fitting top, paper-based bedding, a smooth-sided exercise wheel, wooden chew toys for wearing down teeth, and a nutritious diet of rodent pellets and some fresh produce and grains, plus fresh water daily. 
  • Where can you buy a mouse? Petco Pet Care Centers carry pet mice. Call ahead for availability. 
  • How can you train a mouse? Using favorite treats such as millet and sunflower seeds and gentle handling to encourage desired behaviors such as sitting in a hand or shoulder. 
  • What are different pet mouse noises and what do they mean? Mice produce different squeaks that change in frequency and pitch depending on what they are trying to communicate. They also make scratching sounds with their claws as they run and climb. 

Additional care sheets 

Notes and sources

Ask a Pet Care Center associate about Petco's selection of products available for the care and happiness of your new pet. All products carry a 100% money-back guarantee.

Because all small animals are potential carriers of infectious diseases such as lymphocytic choriomeningitis virus, rat bite fever and Salmonella bacteria, always wash your hands before and after handling your small animal or habitat contents to help prevent the potential spread of disease.

Pregnant women, children under the age of 5, senior citizens and people with weakened immune systems should contact their physicians before purchasing or caring for small animals and should consider having a pet other than a mouse.

Go to the Centers for Disease Control at for more information about small animals and disease.

The information on this Care Sheet is not a substitute for veterinary care. If you need additional information, please contact your veterinarian as appropriate.