This guide covers domestic pet rats, Rattus norvegicus. Plan their home and arrange access to a rat-experienced vet before bringing them home.
Company comes first
Keep compatible rats in pairs or groups. A human companion does not replace another rat. Same-sex groups avoid unwanted litters; mixed-sex groups need veterinary advice about neutering. Introduce unfamiliar rats carefully rather than putting them straight into an established group.
A spacious, ventilated home
Blue Cross recommends a cage at least 90 cm long, 60 cm deep and 120 cm high for two to five rats. This is a starting recommendation, not a reason to restrict space: group size and the animals’ needs still matter.
Choose secure bar spacing, solid flooring and good ventilation. Provide platforms, hammocks, nest spaces, tunnels and climbing opportunities. Keep the cage indoors, away from draughts and direct sun. Use suitable low-dust paper bedding or washable liners; avoid dusty litter and cedar bedding.
Food and water
Use a balanced commercial food formulated for rats. A complete rat pellet or nugget is a straightforward base for a balanced diet. Add small amounts of suitable fresh food within their daily allowance, rather than unlimited treats. Change diets gradually. Fresh water must always be available; check bottles for leaks and blockages.
A daily routine
Remove wet or soiled bedding, check food and water, and provide supervised exploration in a rat-proof space. Hide part of their normal ration in safe enrichment so they can forage. Clean the cage regularly without leaving ammonia to build up.
When to contact a vet
Watch breathing, appetite, movement and body condition. Wheezing, unusual breathing, discharge, weight loss or a change in normal behaviour needs prompt veterinary advice. This guide does not diagnose illness or recommend home-remedy treatments.
Sources checked
Replacement copy checked on 2026-11-08. This is a source-based editorial review, not independent veterinary review.