Mutualism (biology)

organism relationship in which each individual benefits from the activity of the other

behavior in social animals

natural phenomenon in which two or more distasteful species, that may or may not be closely related and share one or more common predators, have come to mimic each other's warning signals

thumb |Myrmecophilous aphids being tended by ants

literary work by Peter Kropotkin on the subject of mutual aid

Afzelia africana seeds bearing [[elaiosomes|right|thumb]] thumb|right|alt=Chelidonium majus diaspores consisting of hard-coated seeds and attached elaiosomes.|Chelidonium majus diaspores consisting of hard-coated seeds and attached elaiosomes

mutually beneficial association between individuals of two species

upright=1.35|thumb|Pseudomyrmex ferruginea ants on a myrmecophyte tree, [[Vachellia cornigera, the bullhorn acacia of Central America]]

A domatium (plural: domatia, from the Latin "domus", meaning home) is a tiny chamber produced by a plant that may be occupied by arthropods.

thumb|Acropyga glaesaria and [[Electromyrmococcus abductus]]

detachable tip found on the pinnules of some species of Acacia and closely related genera

thumb|Camponotus schmitzi in association with its [[myrmecophyte host, Nepenthes bicalcarata]]