How to safely introduce two gerbils: step-by-step guide

Introducing a new gerbil to one you already have requires understanding their natural behaviour and social habits. In the wild, gerbils live in small family groups, interacting through grooming, playing, and mutual care, but will aggressively defend their group from outsiders.

This defensive behaviour arises from fear and uncertainty about unfamiliar gerbils. Building trust gradually is key to a safe introduction, especially for two gerbils over 10 weeks old in captivity. Introducing more than one new gerbil at once is not recommended due to increased risk.

Step 1: Prepare a split cage setup

Use a large cage divided into two sections by a solid barrier or place a smaller cage inside a larger one. This separation allows the gerbils to see, smell, and hear each other without physical contact. Avoid accidental encounters early on, as these can cause aggression and jeopardise the process.

Step 2: Swap gerbils between sides frequently

Swap the gerbils between the two sections several times each day if possible. This exposes each gerbil to the other's scent within their own territory, fostering familiarity and reducing territorial instincts.

Step 3: Maintain swapping for about a week

Continue these swaps over approximately 7 days. You should notice increased curiosity, reduced aggression signs, and possibly gerbils sleeping near the divider. These are positive indicators they are becoming comfortable with each other.

Step 4: Release into the same cage with supervision

After about a week, place both gerbils in the same cage on opposite sides and allow them to explore each other calmly. Stay close for the first 30 minutes to monitor interactions. Light play fighting is normal, including chasing and boxing, but be ready to intervene if serious fighting ensues (characterised by rolling and biting).

Step 5: Continue monitoring and be patient

If they remain passive after initial interactions, you can relax supervision but keep an eye on them for several hours. If fighting occurs, separate them and restart the split cage process, allowing a longer bonding period next time.

Tips to improve introduction success

• Younger gerbils under 10 weeks are more adaptable to new company, while older gerbils (especially over a year) can be stubborn and territorial.
• Dividers can be tricky; consider buying an introduction cage or a small cage insert designed for this purpose.
• Never introduce one gerbil to multiple others as established groups rarely accept newcomers.
• Female gerbils tend to be more territorial and may require longer preparation time before full introduction.

Understanding gerbil behaviour during introduction

Gerbils show aggression primarily as a defensive response to protect their territory or young. When introduced properly, they will express curiosity and engage in social behaviours like grooming.

Brief play fighting during introduction is part of their social assessment and not a cause for alarm if no severe injuries occur. However, if fights escalate, separation and veterinary care for any injuries are essential.

When to seek veterinary help

If aggression results in wounds, seek veterinary advice promptly. Untreated injuries may become infected and cause serious harm. Persistent hostility despite careful introductions may mean the gerbils need to live separately permanently for their welfare.

Conclusion

The split-cage method is the safest and most effective way to introduce two gerbils. It works by gradually building familiarity through scent and sight, reducing fear and territoriality. By respecting gerbils’ natural instincts and being patient, you maximise the chance of a harmonious and happy companionship.

Introducing gerbils requires empathy and vigilance — take your time, watch their behaviour carefully, and always prioritise their health and comfort throughout the process.