Trophallaxis is the exchange of liquid material between individuals, mostly members of the same colony. Wheeler (1918) was the rst to propose the term trophallaxis for describing these interactions between nestmates in ant colonies. He interpreted them as being “clearly cooperative and mutualistic relationships,” and thereby separated his term from the term trophobiosis, which had been suggested earlier by Roubaud (1916) to indicate oral food transfers based on a “trophic exploitation” in social wasps (for review and historical background, see Sleigh 2002).