Uninformed sacrifice: evidence against long-range alarm transmission in foraging ants exposed to a localized perturbation

TL;DR

This study investigates whether foraging ants transmit danger information over long distances, finding that they do not, leading to individualistic escape behavior and reduced foraging activity.

Contribution

It provides empirical evidence that long-range alarm transmission does not occur in Atta insularis ants during localized perturbations.

Findings

Ants do not transmit danger information over large distances.

Localized perturbation causes ants to turn back individually.

Foraging activity decreases due to systematic sacrifice of non-informed ants.

Abstract

It is well stablished that danger information can be transmitted by ants through relatively small distances, provoking either a state of alarm when they move away from potentially dangerous stimulus, or charge toward it aggressively. There is almost no knowledge if danger information can be transmitted along large distances. In this paper, we perturb leaf cutting ants of the species Atta insularis while they forage in their natural evioronment at a certain point of the foraging line, so ants make a "U" turn to escape from the danger zone and go back to the nest. Our results strongly suggest that those ants do not transmit "danger information" to other nestmates marching towards the danger area. The individualistic behavior of the ants returning from the danger zone results in a depression of the foraging activity due to the systematic sacrifice of non-informed individuals.