Editing Swarm behaviour (section)

{{short description|Collective behaviour of a large number of (usually) self-propelled entities of similar size}}
{{Redirect|Swarm}}
{{Use British English|date=August 2021}}
{{Use dmy dates|date=August 2021}}
[[File:Auklet flock Shumagins 1986.jpg|thumb|350px|right|A flock of [[auklet]]s exhibit swarm behaviour]]

'''Swarm behaviour''', or '''swarming''', is a [[collective animal behaviour|collective behaviour]] exhibited by entities, particularly animals, of similar size which aggregate together, perhaps milling about the same spot or perhaps moving ''en masse'' or [[animal migration|migrating]] in some direction. It is a highly interdisciplinary topic.<ref>{{cite book |last1=Bouffanais|first1=Roland|title=Design and Control of Swarm Dynamics|publisher=Springer|isbn=978-981-287-750-5|edition=First|doi=10.1007/978-981-287-751-2|year=2016|series=SpringerBriefs in Complexity}}</ref>

As a term, ''swarming'' is applied particularly to insects, but can also be applied to any other entity or animal that exhibits swarm behaviour. The term ''[[flocking (behavior)|flocking]]'' or ''murmuration'' can refer specifically to swarm behaviour in birds, ''[[herd behaviour|herding]]'' to refer to swarm behaviour in [[tetrapods]], and [[shoaling and schooling|''shoaling'' or ''schooling'']] to refer to swarm behaviour in fish. [[Phytoplankton]] also gather in huge swarms called [[algal bloom|''blooms'']], although these organisms are [[algae]] and are not self-propelled the way animals are. By extension, the term "swarm" is applied also to inanimate entities which exhibit parallel behaviours, as in a [[swarm robotics|robot swarm]], an [[earthquake swarm]], or a swarm of stars.

From a more abstract point of view, swarm behaviour is the collective motion of a large number of [[self-propelled particles|self-propelled entities]].<ref>{{cite journal |author1= O'Loan|author2= Evans|doi= 10.1088/0305-4470/32/8/002|title= Alternating steady state in one-dimensional flocking|year= 1998|journal= Journal of Physics A: Mathematical and General|volume= 32|issue= 8|pages= L99–L105|arxiv= cond-mat/9811336|bibcode= 1999JPhA...32L..99O|s2cid= 7642063}}</ref> From the perspective of the mathematical modeller, it is an [[emergence|emergent]] behaviour arising from simple rules that are followed by individuals and does not involve any central coordination. Swarm behaviour is also studied by [[active matter]] physicists as a phenomenon which is not in [[thermodynamic equilibrium]], and as such requires the development of tools beyond those available from the [[statistical physics]] of systems in thermodynamic equilibrium. In this regard, swarming has been compared to the mathematics of [[superfluids]], specifically in the context of [[Starling#Behaviour|starling flocks]] (murmuration).<ref>{{cite journal |last1=Attanasi|first1= A.|last2= Cavagna|first2= A.|last3= Del Castello|first3= L.
|first4=I.|last4=Giardina
|first5=T. S.|last5= Grigera
|first6=A.|last6=Jelić
|first7=S.|last7= Melillo
|first8=L.|last8= Parisi
|first9=O.|last9= Pohl
|first10=E.|last10= Shen
|first11=M.|last11=Viale|title=Information transfer and behavioural inertia in starling flocks. |journal=Nature Physics |date=September 2014 |volume=10 |issue=9 |pages=691–696 |doi=10.1038/nphys3035 |pmid=25264452 |pmc=4173114 |arxiv=1303.7097 |bibcode=2014NatPh..10..691A }}</ref>

Swarm behaviour was first simulated on a computer in 1986 with the simulation program [[boids]].<ref name="Reynolds">{{cite book |author= Reynolds CW |chapter= Flocks, herds and schools: A distributed behavioral model |year= 1987 |title= Proceedings of the 14th annual conference on Computer graphics and interactive techniques |citeseerx= 10.1.1.103.7187 |volume= 21 |issue= 4 |pages= 25–34 |doi= 10.1145/37401.37406 |isbn= 978-0-89791-227-3|s2cid= 546350 }}</ref> This program simulates simple [[agent-based model in biology|agents]] (boids) that are allowed to move according to a set of basic rules. The model was originally designed to mimic the flocking behaviour of birds, but it can be applied also to schooling fish and other swarming entities.