trophallaxis

thumb|300px|right|Trophallaxis in Asian-Australian weaver ant O. smaragdina, [[Thailand]] Trophallaxis () is the direct transfer of fluid and food (excreted, secreted or regurgitated) between individuals, typically through mouth-to-mouth (stomodeal) or anus-to-mouth (proctodeal) feeding. Along with nutrients, trophallaxis can involve the transfer of molecules such as proteins, hormones, organisms such as symbionts, and information to serve as a form of communication. Trophallaxis is used by some birds, gray wolves, vampire bats, and is most highly developed in eusocial insects such as ants, wasps, bees, and termites. Like lactation, trophallaxis transmits socially transferred materials between bodies.

== Etymology == Trophallaxis is derived from Greek trophé, meaning 'nourishment' and allaxis, meaning 'exchange'. The word was introduced by the entomologist William Morton Wheeler in 1918. Wheeler's original conception was much broader than often recognized. He described the evolution of trophallaxis as an "ever-widening vortex" that began as a mutual trophic relation between parent and offspring but expanded to encompass increasingly complex relationships.