In ecology, commensalism is a kind of relationship between two organisms where one benefits and the other isn't significantly harmed or helped (like a bird living in a tree). The term derives from the English word commensal, meaning "sharing of food" in human social interaction; that word derives from the Latin com mensa, meaning "sharing a table". Types As with all ecological interactions, commensalisms vary in strength and duration from intimate, long-lived symbioses to brief, weak interacti… (More on Commensalism)