White Rats

People usually start searching for “white rats” when they’re weighing up a pet rat purchase: how big they get, what they eat, whether they smell, and what tends to go wrong health-wise. Those decisions matter. A poorly set-up cage or an unbalanced diet doesn’t just make a rat uncomfortable—it can shorten a life that is already brief.

White rats are not a separate species. They’re domestic rats (most often the same species as other pet rats, Rattus norvegicus) with a pale coat because of specific colour genes. Their day-to-day needs are much the same as any other well-bred pet rat: company, clean air, safe chewing, good food, and calm handling.

Quick profile: what most people mean by “white rat”

• Appearance: White coat; eyes may be pink (albino or pink-eyed varieties) or dark depending on genetics.^{1, 2}
• Adult size: Commonly around 200–650 g, with males typically heavier than females; body length roughly 23–28 cm (tail additional).³
• Lifespan: Often 2–3 years in pet settings (some live longer with excellent husbandry).³
• Temperament: Social, curious, quick to learn. Individual personality and early handling matter more than coat colour.^{4, 5}

White coat genetics: why some rats are white with pink eyes

Many “white rats” seen in homes and labs are albino or pink-eyed varieties. In albino rats, mutations affecting melanin production mean pigment doesn’t develop normally in the coat or eyes. In practice, that’s why the fur appears white and the eyes can look pink or red in certain light.^{1, 2}

It’s worth a small caution here: “white” is a description, not a guarantee of a single genetic type. Some rats can appear white due to extreme dilution or particular markings, while still carrying different underlying colour genes.¹

Behaviour: what to expect from a well-kept pet rat

Domestic rats are busy animals. They spend long stretches exploring, climbing, chewing, rearranging nesting, and paying close attention to what changes in their space. Given steady handling, many become calm with people and will readily come to the cage door when they learn routines.^{4, 5}

The most important behavioural “need” is social contact with other rats. A single rat can become withdrawn or stressed. Most welfare guidance recommends keeping rats in compatible same-sex pairs or small groups, with careful introductions and enough space and resources to avoid conflict.^{4, 5}

Housing: air, space, and a life that can’t be bored

A good rat cage is large, well-ventilated, secure, and easy to clean. Wire-sided, “birdcage-style” enclosures generally provide better airflow than enclosed tubs or aquariums, which can trap ammonia and humidity.^{6, 7}

Inside the enclosure, aim for structure rather than emptiness:

• Deep, safe bedding for nesting and burrowing (paper-based options are commonly recommended; avoid sawdust).⁶
• Hide boxes and covered resting spots, so rats can withdraw and sleep out of view.⁶
• Chew materials (untreated wood, cardboard) to support dental wear and normal behaviour.⁶
• Climbing and foraging enrichment (ropes, tunnels, platforms), rotated to keep the environment interesting.⁶

Heat is a quiet risk in Australia. Keep cages out of direct sun and away from hot rooms, and make shade and airflow non-negotiable.⁶

Diet: what “balanced” looks like for rats

Rats are omnivores, but “a bit of everything” can drift into a high-fat seed mix and too many treats. Welfare guidance in Australia commonly recommends a base diet of good-quality rat pellets/cubes, with fresh vegetables and small portions of fruit, and treats kept genuinely small.^{5, 7}

• Every day: fresh water; measured staple pellets/cubes; a mix of vegetables.
• Sometimes: fruit and higher-energy foods in small amounts.
• Go easy on: seeds, grains, and sugary/fatty snack foods—easy to overdo, easy to unbalance.⁵

Health issues to watch (and why early action matters)

Pet rats commonly present to vets for respiratory disease, skin problems, and tumours. Clean bedding, good ventilation, and a stable routine reduce stressors, but they do not remove all risk—rats are prone to certain conditions even with excellent care.^{7, 8}

Common red flags

• Respiratory signs: noisy breathing, repeated sneezing, fluffed coat, lethargy, weight loss.
• Lumps: especially under the skin along the underside; tumours (including mammary tumours) are common in rats and should be assessed promptly.⁸
• Dental problems: drooling, reduced appetite, messy eating, weight loss—can be linked to malocclusion or pain.⁹

If you see any of these, a prompt visit to a vet experienced with small mammals is kinder than “waiting to see”. Rats can go downhill quickly once they stop eating or breathing comfortably.⁷

Breeding basics (useful even if you never plan to breed)

Accidental litters happen fast. Rats can reach sexual maturity while they still look like “babies”, and the gestation period is short. Typical figures used in veterinary references are a gestation of about 21–23 days, weaning at around 21 days, and litter sizes often in the high single digits to low teens (though it varies).³

To prevent unwanted breeding, keep same-sex groups and separate males and females reliably, including before and after weaning age if you are housing a mixed litter temporarily.^{4, 5}

Training and handling: calm hands, clear patterns

Rats learn by repetition and consequence. Gentle, consistent handling and food rewards can teach them to come when called, step onto a hand, or move into a carrier without a chase. Keep sessions short, end on a quiet success, and avoid grabbing from above—many rats interpret that as a threat rather than an invitation.⁷

About “white rats in research” (and a quick correction)

White (often albino) rats have a long history in laboratory research because they breed readily, are manageable in group housing, and have well-described biology across generations. Modern animal research in Australia is governed by ethical oversight and welfare standards for housing and care, including guidance that supports social housing for rats where compatible and appropriate.¹⁰

The earlier draft’s specific claims about “the first recorded use” in 17th-century France and a particular 1906 University of Sydney alcohol-memory study are not well supported as stated, and they’re best left out unless you can verify them with primary historical sources.

Final thoughts

A white rat is, in most practical ways, simply a pet rat with a pale coat. Choose for temperament and health, not colour. Keep them in pairs or small groups, give them clean air and a thoughtfully furnished cage, feed a pellet-based diet with fresh veg, and treat breathing changes or lumps as time-sensitive.

References

1. PubMed: A Tyrosinase missense mutation causes albinism in the Wistar rat
2. PubMed: The rat pink-eyed dilution (p) mutation (genetics of pink eyes and coat dilution)
3. Merck Veterinary Manual: Biologic Data of Pet Rodents (rat lifespan, weights, gestation)
4. RSPCA Knowledgebase: How should I care for my rats?
5. RSPCA Knowledgebase: What company do my pet rats need?
6. RSPCA NSW: How to care for your rat (housing, bedding, heat protection)
7. Agriculture Victoria (Animal Welfare Victoria): Caring for pet rats and mice
8. Merck Veterinary Manual: Disorders and Diseases of Rats (tumours and other common problems)
9. University of Missouri College of Veterinary Medicine (DORA): Rats (conditions including malocclusion)
10. Agriculture Victoria: Code of Practice for the Housing and Care of Laboratory Mice, Rats, Guinea Pigs and Rabbits (Part 3.2)