Editing Swarm behaviour (section)

===Emergence===
{{Main|Emergence}}

The concept of emergence—that the properties and functions found at a hierarchical level are not present and are irrelevant at the lower levels–is often a basic principle behind [[self-organization|self-organizing systems]].<ref name="importance-ppt">{{cite web |url=http://www.authorstream.com/Presentation/wdorsey-88049-hierarchy-life-biology-education-ppt-powerpoint/ |access-date=6 October 2009 |title=Hierarchy of Life |date=14 September 2008 |archive-date=3 July 2016 |archive-url=https://web.archive.org/web/20160703121704/http://www.authorstream.com/Presentation/wdorsey-88049-hierarchy-life-biology-education-ppt-powerpoint/ |url-status=dead }}</ref> An example of [[biological organisation|self-organization in biology]] leading to emergence in the natural world occurs in ant colonies. The queen does not give direct orders and does not tell the ants what to do.{{citation needed|date=July 2018}} Instead, each ant reacts to stimuli in the form of chemical scents from larvae, other ants, intruders, food and buildup of waste, and leaves behind a chemical trail, which, in turn, provides a stimulus to other ants. Here each ant is an autonomous unit that reacts depending only on its local environment and the genetically encoded rules for its variety. Despite the lack of centralized decision making, ant colonies exhibit complex behaviours and have even been able to demonstrate the ability to solve geometric problems. For example, colonies routinely find the maximum distance from all colony entrances to dispose of dead bodies.