People usually land on a fancy rat care guide when they’re weighing up a new pet (or trying to fix the first week of chaos after bringing rats home): How long do they live, do they need a friend, what should the cage look like, and what problems should send you to the vet.
Fancy rats are bright, busy little mammals. Get the housing, diet and companionship right and they tend to settle into calm, curious routines. Get it wrong and you’ll often see stress, squabbles, respiratory trouble, and a much shorter, harder life.
Fancy rat quick facts
- Species: Domesticated brown rat (Rattus norvegicus).1
- Typical adult size: Often around 20–25 cm body length (tails are additional). (This varies by sex and line.)
- Typical lifespan: Commonly around 2–3 years (sometimes longer with good care).2, 6
- Social needs: Not a solitary pet; best kept in same-sex pairs or small groups.2, 5
- Common health concerns: Respiratory disease is common; tumours (especially mammary) are also common in pet rats.7, 8
What “fancy rat” means (and where pet rats came from)
“Fancy rat” is the everyday name for the domesticated form of the brown rat. The word fancy comes from “animal fancy”: people breeding and keeping animals for colour, coat type and temperament, not for work.1
Modern fancy rats were developed through selective breeding in Europe, with organised showing documented in England in the early 1900s.1 The important takeaway for owners is simple: today’s pet rats are not wild animals in a cage. They are domesticated, highly social, and shaped by generations of living closely with people.
Types of fancy rats (coat, ears and markings)
What many people call “breeds” in rats is usually a mix of coat type, ear type and colour pattern. You’ll commonly see:
- Markings/patterns: hooded, Berkshire, self (solid), and more.
- Coat types: standard (smooth), rex (wavy/curly), satin (glossier).
- Ear type: standard ears or “dumbo” (set lower and wider on the head).
These traits affect look and feel more than care. Focus your choice on temperament, health history, and whether you can keep at least two compatible rats.
Companionship: one rat is rarely the right answer
Rats are group-living animals. Kept alone, many become withdrawn or restless, and you’ll often see more bar chewing, pacing, and “always-on” attention seeking. Most welfare guidance recommends keeping rats in pairs or small groups of their own species.2, 5, 3
- Best starter set-up: two or three same-sex rats of a similar age.
- Avoid surprise litters: keep males and females separate unless you have desexed animals and a vet plan.
- Stability matters: rats often do better when group composition stays steady, rather than frequent additions and removals.3
Housing: tall space, safe spacing, easy cleaning
A good rat enclosure feels like a small, vertical landscape: shelves, ramps, ropes, hammocks, hiding places. Ventilation matters. So does cleaning access, because ammonia build-up irritates airways.
What to look for in a cage
- Room to move: bigger is always easier to enrich and to keep clean. As a practical guide, Blue Cross suggests a minimum of about 90 cm (L) × 60 cm (D) × 120 cm (H) for two to five rats, with larger housing for larger groups.6
- Ventilation: wire cages generally ventilate better than solid tanks; avoid stale, humid set-ups.
- Safety: bar spacing must be small enough to prevent escapes (especially for young rats).
Bedding, nesting and enrichment
Rats are driven to forage, climb, nest, explore and manipulate their environment. Enrichment isn’t a luxury; it’s normal behaviour made possible.4
- Bedding: use low-dust, absorbent bedding. If any bedding seems to trigger sneezing or irritation, swap it out.
- Hide and nest: provide enclosed sleeping spots and nesting material (paper-based options are commonly used).2
- Climb and chew: add ropes, ladders, tunnels, chew-safe items, and rotated toys to keep the space “alive”.2, 4
Diet: pellets first, vegetables daily, treats kept small
Rats are omnivores, but they do best when their main diet is a nutritionally complete rat pellet or cube, with fresh foods added in small amounts. RSPCA guidance recommends good quality rat pellets/cubes as the foundation, with small amounts of vegetables as part of the daily allowance rather than “extra”.9, 5
A steady, sensible feeding pattern
- Base diet: quality rat pellets/cubes.9
- Vegetables: small daily amounts (think dark greens and non-starchy veg).9
- Fruit and treats: occasional, small portions; easy to overdo and push weight up.5, 9
- Water: fresh water available at all times (bottle or suitable dish).2
Rats also need opportunities to gnaw and chew as part of normal behaviour and dental wear.9, 5
Exercise and handling: daily movement, calm hands
Healthy rats move. They climb, hop, investigate corners, and keep going long after you’ve stopped watching. Build that movement into daily life with climbing space in the cage and supervised time outside it in a rat-proofed area.
Regular gentle handling helps rats stay calm around people. Animal Welfare Victoria notes they must be handled regularly to develop a positive relationship with humans, and mishandling can lead to bites.2
Common health issues (and when to see a vet)
Pet rats are small, fast-metabolism animals. When they become unwell, they can deteriorate quickly. If something feels “off”, it’s worth an early call to an experienced vet.
Respiratory disease
Respiratory disease is one of the most common health problems in rats, with several infectious agents involved (including Mycoplasma pulmonis).7 Seek veterinary advice promptly if you notice:
- noisy breathing, wheezing, or laboured breathing
- persistent sneezing or “snuffling”
- discharge around the nose or eyes
- reduced appetite, hunched posture, or sudden tiredness
Tumours (especially mammary tumours)
Rats are prone to developing tumours; mammary fibroadenomas are described as the most common tumours in rats, and early veterinary assessment improves options for treatment.8 Any new lump is worth checking, even if your rat seems otherwise normal.
Introducing rats (and other pets): caution beats optimism
Introducing rats to new rats is usually possible, but it should be slow and controlled. Start with scent swaps and gradual, supervised meetings in neutral territory. Watch for tension and chasing that doesn’t settle, and be ready to separate.
Introducing rats to cats or dogs is a different story. Even a calm predator can injure a rat in a moment, and stress alone can be harmful. Keep interactions separated and secure: rats safe behind closed doors or in a predator-proof space, not “loose on the couch together”. Animal Welfare Victoria specifically notes housing must protect rats from predators such as dogs and cats.2
Final thoughts
Fancy rats suit people who like small animals with big behavioural lives: busy nights, careful hands, and social bonds that are real, even if they’re expressed quietly. If you can provide space, companionship, a pellet-based diet, and prompt veterinary care when needed, rats are often one of the most rewarding small pets to live with.2, 5
References
- Wikipedia — Fancy rat (overview and history)
- Agriculture Victoria (Animal Welfare Victoria) — Caring for pet rats and mice (updated 28 Nov 2025)
- Agriculture Victoria — Code of Practice: Housing and care of laboratory rodents (Part 3.2 animal enclosures; social housing guidance)
- Agriculture Victoria — Code of Practice: Behaviour and environmental enrichment (Part 3.4)
- RSPCA Australia Knowledgebase — How should I care for my rats?
- Blue Cross — Caring for your rat (lifespan, companionship, cage size guidance)
- Merck Veterinary Manual — Mice and rats as pets (respiratory disease and pathogens)
- Merck Veterinary Manual — Disorders and diseases of rats (tumours, including mammary fibroadenomas)
- RSPCA Australia Knowledgebase — What should I feed my rats?
Veterinary Advisor, Veterinarian London Area, United Kingdom