For centuries, designers and engineers have looked to the natural world for inspiration in an effort innovate their products and services. The Wright brothers drew inspiration for their early gliders and later the ‘Wright Flyer’ while watching and analyzing the flight of birds. More recently, bioengineers at Boston Dynamics have created biped and quadruped balancing robots that emulate animals and their movements in the natural world (e.g., the Atlas, Cheetah, and Wildcat robots). Engineers at the University of Pennsylvania are developing low-cost flying micro robots that work in swarms, similar to bees or birds, in an effort to improve emergency response operations. Similarly, social scientists have borrowed from biological or ecological theory for new insights on how policies might change or how humans might socialize with one another. Frank Baumgartner and Bryan Jones’s (1993) punctuated equilibrium theory borrows from evolutionary biology to describe long stagnations in policy arenas punctuated by periods of rapid policy change. Similarly, John M. Gaus (1947) borrowed from the ecology literature to explain how environment and context matter to public administration and management. To better explain the structure and motives of collaborative relationships, this paper examines the parallels between nonprofit networks and cooperative behavior found in nature. Eusociality is considered an advanced organizational arrangement that reflects the development of integrated behaviors, signified by: a clear division of labor, commonly relating to reproduction; cooperative care of young; and overlapping generations, whereby more capable generations help less capable, either taking care of offspring or elderly members. Eusocial behavior in nature is relevant to collaboration among charitable organizations, as it relies on an understanding of the relatedness of the organisms participating in cooperative activities. While in nature this shared purpose is most easily understood by examining genetic similarity, in charitable organizations it can be understood by the similarity of organizations’ missions. This chapter proposes a new theoretic lens for thinking about the ways in which organizational similarity acts as an antecedent to decisions to cooperate, conditioning each organization’s assessments of costs and benefits. Further, this chapter posits that collaboration among nonprofit organizations cannot be understood without accounting for the relatedness of nonprofit organizations. Unlike for-profit firms, nonprofits can have primary purposes or missions that they share with other nonprofit organizations. These shared missions can serve as critical antecedents to collaboration and condition organizations’ perceptions of potential collaborative endeavors. To develop this proposed lens, we first briefly examine the literature on nonprofit collaboration. Particular attention is paid to the role of hierarchy and structure in nonprofit collaboration. The benefits and costs of collaboration are also considered. Next, the biological concept of eusociality is examined in order to relate this biological understanding to cooperative decisions by charitable organizations, followed by propositions and a typology of hierarchy within nonprofit organizations. Finally, implications are discussed.