Rabbits may exhibit fighting or aggressive behavior when they are introduced to a larger living space for a few reasons:

1. Territorial Behavior: Rabbits are territorial animals, and they become accustomed to the space they inhabit. Moving them to a new, larger area can disrupt their sense of territory, causing them to defend their perceived boundaries.

2. Hierarchy Establishment: Rabbits establish a social hierarchy within their group. When introduced to a new space, they may engage in dominance behaviors and territorial disputes to establish their rank and assert control.

3. Stress and Fear: A sudden change in environment can be stressful for rabbits, leading to heightened anxiety and defensive behavior. They may interpret the larger space as unfamiliar and potentially threatening, triggering defensive reactions.

To minimize fighting and help rabbits adjust to a larger living space more smoothly, consider the following tips:

1. Gradual Transition: Instead of immediately moving the rabbits to a much larger space, gradually increase their living area over time. Start by providing an intermediate-sized enclosure and gradually expand it over several days or weeks. This allows them to become familiar with the new space in a more manageable way.

2. Scent Familiarity: Introduce the rabbits to the new space with familiar scents. Place some of their old bedding or a small piece of their old hutch in the new area to provide a sense of familiarity and comfort.

3. Provide Hiding Places: Offer hiding spots or shelters within the larger space where rabbits can retreat to if they feel overwhelmed or threatened. These hiding places can help reduce stress and provide a sense of security.

4. Monitor the Rabbits: Keep a close eye on the rabbits during the transition period to ensure their safety and intervene if aggressive behavior escalates. Separate rabbits if necessary to prevent injuries and gradually reintroduce them when they have adjusted to the new environment.

Remember, each rabbit has its own unique personality, and the adjustment period may vary for different individuals. Patience, gradual transitions, and providing a stress-free environment can help minimize fighting and help rabbits adapt to larger living spaces more comfortably.