“In man, social intercourse has centered mainly on the process of absorbing fluid into the organism, but in the domestic dog and to a lesser extent among all wild canine species, the act charged with most social significance is the excretion of fluid. For man the pub, the estaminet, the Biergarten, but for the dog the tree trunk, the lintel of door or gate, and above all the lamppost, form the focal points of community life. For a man, the flavors of alcoholic drinks, but for a dog the infinitely variegated smells of urine are the most potent stimuli for the gregarious impulse.”
From The Lamppost, A Study of the Social Life of the Domestic Dog by Sirius (quoted in Sirius by Olaf Stapledon)
Humans communicate largely by the spoken and written word. (Hence this book.) Dogs, however, employ several different “languages”