Dogs ‘know’ a secret that humans have forgotten: when you lick each other, or kiss, you share uniquely cultivated local commensal bacteria, some of which are conserved in the recipients. This means, literally, ‘we now share bodies’; the uniquely evolved commensals still with you form a kind of ‘radar love’ with their gap-crossing progeny. It’s one of the paths for telepathy. 90% of your cells are bacterial.