Running in the rain: Impact of water droplets on tandem running recruitment in a tropical ant

Abstract Rain hampers essential activities like foraging, guarding, and frequently causes damage to the dwelling, especially for organisms like ants that live in subterranean nests. Diacamma indicum , a tropical ant, is known to relocate to higher ground using tandem running and to build nest mounds when it faces rain during the monsoon. We investigated what happens if these ants have to relocate when water droplets are falling on them. This question was addressed by subjecting treatment tandem pairs to water droplets on their bodies (a proxy for low‐level rainfall) along their journey to the new nest and comparing it with controls. The outcome suggested that individual treatment tandem runs showed a significantly higher number of interruptions during the trip and failures to complete the tandem run to a new nest. The location at which the treatment was given (near the old nest, midway or near the new nest) did not influence the outcomes (success or failure to reach the new nest). Despite low levels of water falling on them, tandem leaders continued to recruit to the new nest. They completed their relocation without any significant change in the dynamics, thus taking no longer than control colonies to complete transport. This experiment shows the credibility of the tandem run as a robust method of transportation even under adverse environmental conditions like rain and highlights the need to explore how subterranean organisms like ants have adapted to the monsoon and manage their lives through the months of heavy rainfall.