Species · Small Pet

Rat

Rattus norvegicus domestica

The fancy rat, domesticated from the brown rat and kept since the 1900s — the most companionable rodent there is.

Ask any exotics vet or zookeeper what small pet they would actually own and an unreasonable number say the rat. Rats learn their names, ride shoulders, play games and greet you at the bars — the bond is real, not projected. The costs are two: the lungs and the calendar. Respiratory disease is the species’ shadow, and even a healthy rat gives you only a couple of years. Keep them in pairs or groups, buy from clean lines, and accept that the price of the best rodent is the shortest goodbye.

At a glance

Lifespan: 2–3 years
Adult weight: 250–600 g
Daily attention: 1–2 hrs out of cage daily
Alone time tolerated: Keep in same-sex pairs or groups, always
Minimum housing: Tall barred cage with hammocks and levels
Diet: Rat blocks plus fresh food; ration it — they are gourmands
Handling: Excellent — the best-handling animal on this page
With children: Genuinely good with respectful children
With other pets: Prey animal — keep separate from cats and dogs

Breeds · 4 listed

Ear-set and coat varieties from show breeding. A dumbo is not a different pet, just differently upholstered.

Standard
Dumbo
Rex
Hairless

Right for you if

You want a small pet that interacts like a tiny dog.
Two or more animals, housed and handled daily, is the plan.
An exotics-capable vet is reachable and the budget includes them.
You can love something properly for two or three years, knowingly.

Wrong for you if

The short lifespan is a dealbreaker — better to know now.
One rat alone in a cage was the picture; that is a diminished animal.
Anyone in the house cannot get past the tail.
Respiratory-illness vet visits would be deferred until payday.

Welfare and sourcing — read this part

Chronic respiratory disease — murine respiratory mycoplasmosis — is the species’ defining illness, causing both immediate and lifelong respiratory problems, and rats with it rarely live past two.¹ Buy from lines that sound clear — no clicking, chattering or sneezing anywhere in the colony — and treat new-rat quarantine as standard.
Mammary fibroadenomas are the most common tumours in rats; most stay benign.¹ They can grow startlingly fast, so a weekly check under the arms and along the belly, and an early vet visit for any lump, is the routine that keeps them operable.
Meet the colony, not just the rat: a clean cage, clear breathing throughout and confident animals that approach the front is the health certificate that matters at this price point.

Sources

Disorders and Diseases of Rats. MSD Veterinary Manual 2026. Accessed 2026-09-05. International MSD Veterinary Manual Chronic respiratory disease (murine respiratory mycoplasmosis) causes both short- and long-term respiratory illness in rats, and rats with it rarely live longer than two years. Mammary fibroadenomas are the most common tumours in rats, and most do not become malignant.

Every source here was checked, not recalled. Where this page makes a health statement and no source appears against it, that is not an oversight we have hidden — it means the claim is not yet sourced, and the build reports how many are in that state.

Availability, registration and keeping requirements differ from place to place. Check the rules where you live before you commit to any animal — we describe animals, not law.