Mice as Pets: A Comprehensive Guide for Australian Pet Owners

People usually start looking into pet mice when they want a small companion animal that fits neatly into a unit or a busy routine — but they still want a living creature with real needs, not a decoration in a cage. The difference between mice that merely “get by” and mice that thrive often comes down to a few quiet details: ventilation, temperature, diet quality, and how they’re housed together.

Pet mice can be hardy, alert little animals, but they’re also sensitive to heat, stale air and stressful living arrangements. Below is a practical, Australia-focused guide to choosing mice, setting up housing that supports natural behaviour, feeding them well, and recognising early signs of trouble.

Are mice good pets?

Mice can suit people who enjoy watching natural behaviour up close: climbing, nesting, foraging, grooming, and quick, careful exploration. They don’t need a backyard, and their daily care is usually manageable — but they do need a clean, well-ventilated enclosure, regular interaction, and company of their own species in a safe arrangement.^{1, 2}

Before you bring mice home

Choose the right group

Mice are social and generally do best with companions, but not every pairing is safe. In most homes, a small group of females is the simplest option.^{1, 6}

• Keep at least two mice so they can sleep together, nest, and share normal social contact.^{1, 4}
• Avoid housing entire (undesexed) males together, as fighting can be a real issue.¹
• Separate males and females unless you have a deliberate breeding plan (and the experience and veterinary support to manage it). Mice breed quickly.^{4, 6}

Plan for veterinary care

Find a vet who is comfortable with small mammals before there’s an emergency. If you’re unsure, ring clinics and ask directly whether they see mice regularly.⁶

History and domestication (quick context)

Most pet mice are domesticated forms of the house mouse (Mus musculus). Their long use in laboratory settings has also shaped modern knowledge about mouse nutrition, housing and health — useful, practical information when it’s applied with welfare in mind.⁷

Physical characteristics of pet mice

Size and appearance

Pet mice are small-bodied with a long tail, prominent whiskers and excellent hearing and smell. Coat colours and textures vary widely due to domestication and selective breeding.

What those traits mean in day-to-day care

That sensitive nose and fast metabolism are part of why clean air, low-dust bedding and fresh water matter so much. A mouse doesn’t have to look “sick” for poor ventilation or ammonia build-up to start irritating its airways.²

Temperament and behaviour

Mice are naturally curious and spend much of their waking time investigating scent, structure and movement. Many become calm around gentle handling, especially when it starts young and stays predictable.^{1, 6}

Children and other pets

• Children: Mice can suit older, gentle children with close supervision. They should be supported with two hands, and never lifted by the tail.¹
• Other pets: Keep mice physically separate from cats and dogs. Even “friendly” attention can be stressful, and a single paw swipe can be catastrophic.

Housing and environment

Choose a well-ventilated enclosure

A roomy enclosure with strong ventilation and a solid base for deep bedding is a reliable starting point. Poor ventilation lets humidity and ammonia build up, which can irritate airways and contribute to respiratory disease.^{1, 2}

Avoid aquariums and many plastic tubs as permanent housing because they often don’t ventilate well enough. Wooden enclosures can absorb urine and are difficult to disinfect properly.¹

Space, layout and “mouse architecture”

Instead of chasing a perfect centimetre measurement, aim for as large as practical, then make it complex. Mice use space in layers: they climb, tunnel, hide, and build nests.^{1, 2}

• Deep, low-dust bedding for digging and foraging
• Nesting material (shredded paper works well)
• Multiple hide options with more than one exit (small boxes, tubes)
• A solid running wheel sized so the back doesn’t arch
• Chew items to support gnawing behaviour and dental wear^{2, 7}

Temperature and humidity

Mice have limited ability to regulate body temperature and are sensitive to heat. A commonly recommended housing range is about 18–26 °C with 30–70% relative humidity, and cages should be kept out of direct sun. Temperatures above about 30 °C can lead to heat stress and heat stroke, especially in crowded enclosures.⁴

Diet and nutrition

The foundation: formulated mouse pellets

Use a good-quality pellet formulated for mice as the base diet. Seed mixes are often a poor choice because mice selectively eat the fattiest pieces and leave the balanced parts behind, leading to nutritional imbalance and obesity risk.^{2, 7}

Fresh foods (small amounts, chosen carefully)

Supplement with small serves of safe vegetables as part of the daily allowance (not “on top of” unlimited pellets). Fruit is best treated as an occasional extra, offered in tiny portions.^{2, 7}

Water

Provide fresh water at all times. Water bottles are often cleaner than bowls, but they must be checked daily for blockages or leaks; having more than one bottle reduces the chance of a failure going unnoticed.⁷

Health and lifespan

With good care, many pet mice live around 1–3 years, and some sources note they can live longer under ideal conditions. Lifespan varies with genetics, sex, and health history.^{4, 6}

Common health problems to watch for

• Respiratory disease: sneezing, clicking sounds, rapid breathing, crusty eyes/nose, reduced activity. Housing conditions (ventilation, dust, ammonia build-up) matter.^{2, 3}
• Lumps and tumours: more common as mice age; any new lump needs veterinary assessment.
• Parasites and skin issues: itching, scabs, hair loss, excessive scratching.
• Dental problems: overgrown incisors if gnawing needs aren’t met or if illness interferes with normal wear.^{2, 7}

Quiet “early warning” signs

• Hiding more than usual, or not coming out to eat
• Weight loss, hunched posture, rough coat
• Wetness around the tail or eyes
• Sudden changes in how cage-mates interact

Mice can deteriorate quickly. If you’re seeing these changes, treat it as urgent and speak with a vet promptly.⁶

Cleaning and routine maintenance

Cleanliness is not just about smell. In a small enclosure, stale air and damp bedding allow ammonia and irritants to build up. That can inflame sensitive airways and set the scene for chronic respiratory trouble.²

• Daily: remove wet bedding patches and leftover fresh foods.
• Weekly (typical minimum): a thorough clean with warm, non-fragrant soapy water, fresh bedding, and refreshed nesting material.¹

Keep some familiar nesting material aside during cleans. Too-perfect sterility can be stressful; mice settle faster when their home still smells like “their” colony.

Handling, training and socialisation

Start with short sessions. Let mice approach your hands rather than chasing them around the cage. Support the whole body, and avoid tail handling entirely.¹

Food rewards can help, but keep treats small and infrequent. The goal is predictable, low-stress contact — a mouse that chooses to climb onto a hand is usually calmer than one that has been grabbed.

Fun facts (kept brief)

Mice communicate in ways humans often miss, including ultrasonic vocalisations. Much of their active life happens at night, when the room is quiet and the enclosure feels safest.⁷

Final thoughts

A good mouse enclosure looks busy and a little untidy: deep bedding, tunnels, nest corners, chew marks in cardboard. That’s often a sign the basics are right. Give them clean air, steady temperatures, a proper pellet diet, and a stable social group, and you’ll see the small, precise rhythms of mouse life unfold at close range.^{1, 2, 4}

References

1. RSPCA Australia — Caring for pet mice
2. RSPCA Knowledgebase — How should I care for my mice?
3. Merck Veterinary Manual — Management of laboratory animals (ventilation, humidity and environment guidance relevant to mice)
4. Merck Veterinary Manual — Special considerations for mice (temperature, humidity, social housing)
5. RSPCA WA — Pocket pets (adopting a rat or mouse; housing, diet and heat stress notes)
6. Agriculture Victoria (Animal Welfare Victoria) — Caring for pet rats and mice
7. RSPCA Knowledgebase — What should I feed my mice?