trophallaxis

Trophallaxis is a social feeding behavior in which one individual transfers liquid food or other fluids to another through mouth-to-mouth exchange. It is most well documented in eusocial insects such as ants, termites, and honeybees, though similar exchanges are observed in a range of social animals. The transfer is typically achieved by regurgitation from a donor to a recipient and may occur in reciprocal or unidirectional forms.

During trophallaxis, a donor regurgitates alimentary contents (nectar, honey, or partially digested food) into the mouth or foregut of the recipient. The recipient consumes the liquid and may subsequently pass on food to others, creating a chain of sharing. In many species, the behavior also serves to spread chemical cues, hormones, and gut microbes that help synchronize colony function and immunity.

Key functions include provisioning nestmates lacking access to foraging, distributing nutrients during colony growth, and facilitating larval development. Trophallaxis also reinforces social organization by disseminating information about food sources, colony status, and recognition cues, thereby contributing to colony cohesion.

It can also spread pathogens or parasites between individuals, though social insects often possess immune adaptations and microbiome sharing that mitigate risks. The practice is considered a cornerstone of colony-level cooperation and division of labor in many species.