To prevent aggression in pet rabbits, it is important to provide them with a spacious and enriching environment, plenty of mental and physical stimulation, and regular handling to build trust and familiarity. Neutering or spaying can also help reduce aggressive behaviors in rabbits. It is essential to observe and understand your rabbit's body language and behavior to address any signs of stress or discomfort promptly. Additionally, ensuring a balanced diet and routine veterinary check-ups can contribute to your rabbit's overall well-being and potentially reduce aggressive tendencies.