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arXiv · 2603.26226

Braess's paradox in tandem-running ants: When shortest path is not the quickest

Joy Das Bairagya·Udipta Chakraborti·Sumana Annagiri·Sagar Chakraborty
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Abstract

Braess's paradox -- where adding network capacity increases travel time -- is typically attributed to selfish agents. Although eusocial colonies maximize collective fitness, we find experimentally that \emph{Diacamma indicum} ants exhibit this paradox: Leaders favour the shortest path even when it slows the colony. We present a quantitative model of the exploration-exploitation trade-off, demonstrating that evolutionary forces selecting for shortest-path identification can force suboptimal global states. This proves the paradox can emerge in highly cooperative systems without individual selfishness.

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Joy Das Bairagya, Udipta Chakraborti, Sumana Annagiri, Sagar Chakraborty. 2026-03-27. Braess's paradox in tandem-running ants: When shortest path is not the quickest. https://arxiv.org/abs/2603.26226

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