Rabbits primarily communicate with each other through body language, vocalizations, and scent marking. They use various forms of body language such as thumping their hind legs, grooming each other, and displaying dominance or submission postures. They also make different vocalizations like grunts, purring, and soft teeth grinding to express emotions or warn others of danger. Additionally, rabbits use scent marking with their chin glands and scent glands located under their chin, on their feet, and near their tails to mark their territory and communicate with other rabbits.