I am often asked how bunnies communicate to each other and us when they just sit there?  The answer is simple: olfaction. The technical term, Chemosensory Communication, refers to their ability to literally taste air. They emit glandular secretions based on moods that they can both smell and taste. So, in essence, they know what each other is feeling. How, you ask? A bunny's nose (rhinarium) is a tremendously complex organ that serves several purposes: warming air to elevate their body temperature, moistening air when they are too warm, conveying messages, understanding environmental stimuli, triggering memory-based associations, detecting predators as well as toxins, and for identifying foods. 
     The vomeronasal organ plays a major role as a pumping mechanism that takes in airborne chemical stimuli when ducts open allowing particles to directly enter the nasal cavity and indirectly enter the oral cavity. These signal messages are interpreted by the brain. The ducts of the lumen (turbinates), covered laterally and medially, are made up of veins, arteries, nerves, glands, and tissue. They open and close up to 120 times per minute and can completely stop. The rate at which they move is noticed by other bunnies as it indicates temperature, health, respiration rate, etc. 
        The olfaction process is the primary and superior sensory modality for them. Any scents connected with previous experiences become memories they recall in subsequent associations. Bunnies noses give me tremendous insights into their thoughts relevant to motives, moods, comfort level, how their perceive situations. I use this information during bonding to predict and interpret behavior. 

   Bunnies, despite needing assistance from humans during bonding, have the upper hand in it. Why, you ask? The answer lies in their extraordinary use of senses. Humans have only a fraction of the olfactory sense that bunnies do. Their sense of smell detects secretions from scent glands. They have a similar Endocrine system to ours whereby each of our essential bodily functions such as metabolism, responses to stimuli like stress, growth, moods, appetite, emotions, and sleep releases hormones into the bloodstream while simultaneously monitoring levels. Each hormone has a specific scent that humans cannot smell but, the exceptional bunny nose can. Not only do they smell this information, they assign values to them. Bunnies can also release hormones by secreting them at will. Chinning, rubbing, urinating, and depositing fecal waste are all ways bunnies deposit scents. When a bunny is agitated during a bonding session, the other bunny knows it long before the bunny indicates it visually for a human to interpret. Conversely, when a human during the bonding process is nervous, the bunnies know about it. It is almost as if they can read our minds. In this way, they have the bonding advantage over us. Humans must rely only on behavior cues while buns have vision and scent.