Social isolation causes mortality by disrupting energy homeostasis in ants
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Social deprivation can have negative effects on the lives of social animals, including humans, yet little is known about the mechanisms by which social withdrawal affects animal health. Here we show that in the carpenter ant Camponotus fellah, socially isolated workers have a greatly reduced life span relative to ants kept in groups of ten individuals. By using a new tracking system, we found that social isolation resulted in important behavioral changes and greatly increased locomotor activity. The higher activity of single ants and their increased propensity to leave the nest to move along the walls suggested that the increased mortality of isolated ants might stem from an imbalance of energy income and expenditure. This view was supported by the finding that while isolated ants ingested the same amount of food as grouped ants, they retained food in the crop, hence preventing its use as an energy source. Moreover, the difference in life span between single and grouped individuals vanished when ants were not fed. This study thus underlines the role of social interactions as key regulators of energy balance, which ultimately affects aging and health in a highly social organism.
KeywordsSocial insect Behavior tracking Social isolation Energy homeostasis
We thank A. Hefetz for collecting queens, A. Crespi for the technical support for the tracking system, and the Swiss Institute of Bioinformatics for the data storage. We are grateful to M. Miura for the helpful discussion and O. Rueppel and two reviewers for useful comments. This work was funded by several grants from the Swiss National Science Foundation, the Japan Society for the Promotion of Science, and an advanced ERC grant. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Conflict of interest
We declare no conflict of interest.
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