 These three sub-categories of biological individual need not be mutually exclusive when considering any particular individual. For example, a given bacterium, such as an individual Buchnera bacterium, may both be an organism itself and be part of a corporate organism, such as the human whose gut it is integral to (Andersson 2000). Likewise, some groups, such as the colonies of eusocial insects sometimes called “superorganisms”, or highly integrated multispecies communities, may be true organisms. This kind of view may also capture what truth lies behind proposals to extend the term organism both to some parts and some groups of organisms (e.g., Queller 1997; Okasha 2011): parts of organisms (such as symbiotic gut bacteria), as well as groups of organisms (such as colonies of ants or bees), are really organisms as well. 