Hi. We have had Daisy (girl, aged 4) and Sushi (boy, aged 5) for five years. They are very bonded. Three months ago we got another pair of very bonded bunnies from the local shelter - 2 girls (Luna and Rosie, sisters aged 2). All 4 bunnies are neutered / spade. Over the past three months we have been slowly trying to bond all 4 bunnies as ideally we would like them to play / live / sleep together. Both pairs of bunnies have their own huge sleeping quarters and they all have a huge outside area to run around during the day (separated by a fence - the pairs can see each other but can't get at each other). We put both pairs of bunnies in their separate sleeping quarters each night. We regularly bring each pair inside for cuddles and play time with their humans. Sometimes we bring all 4 bunnies inside to see how they feel about each other. We always stay with them - however usually run after each other / they nip each other with fur being pulled out. What can we do to being able to leave them all together by themselves? Thanks so much in advance. Mardi (Melbourne, Australia).