How can I introduce another rat to a rat? - briefly
Start with a short, supervised session in a neutral enclosure, using a mesh divider so the animals can sniff each other without direct contact; then gradually increase their time together while watching for calm or dominant behavior. If any aggression occurs, separate them immediately and repeat the process with longer barrier periods before allowing physical interaction.
How can I introduce another rat to a rat? - in detail
Introduce a new rat to an existing one only after both have been examined by a veterinarian and cleared of parasites, respiratory infections, and other health issues. Quarantine the newcomer for at least two weeks in a separate cage to monitor for latent illness.
Prepare a neutral area that neither rat has claimed as territory. Remove familiar bedding, toys, and food dishes from both cages, then place fresh, clean items in the introduction space. Exchange scents beforehand by swapping a small amount of bedding between cages, allowing each animal to become accustomed to the other's odor without direct contact.
Begin the first encounter with a short, supervised session lasting five to ten minutes. Keep the rats on a low‑profile surface where they cannot hide, and watch for specific behaviors: sniffing, grooming, and calm exploration indicate acceptance; lunging, biting, or prolonged chasing signal aggression. If tension arises, separate the animals immediately and try again later.
Gradually extend the duration of supervised meetings, increasing the number of sessions each day. Provide multiple food bowls, water dispensers, and hiding spots to reduce competition. Observe the hierarchy formation; dominant individuals may claim preferred resources, but constant access for subordinates prevents stress.
Maintain the pair together long enough for stable social bonds to develop, typically several weeks. Continue monitoring for signs of injury, weight loss, or excessive grooming. Once confidence is established, merge the cages, ensuring ample space, enrichment, and separate nesting areas to accommodate any lingering dominance behaviors. Regular health checks and environmental enrichment sustain a harmonious cohabitation.