No evidence for tactile communication of direction in foraging Lasius ants

Abstract

The idea that ants communicate when meeting on a trail is beguiling, but evidence for this is scarce. Physical communication in ants has been demonstrated to play a role as a modulator of behaviours such as alarm and recruitment. Honeybees can communicate the location of a resource using an advanced motor display the waggle dance. However, no equivalent of the waggle dance has been described for any ant species, and it is widely believed that ants cannot communicate the location of resources using motor displays. One group of researchers report several demonstrations of such communication in Formica ants; however, these results have been largely ignored. More recently some evidence arose that Lasius niger foragers returning from a food source can communicate to outgoing foragers the direction that should be taken at the next bifurcation by means of physical contact on the trail. Here, we make a concerted effort to replicate these results. Although initial results seemed to indicate physical communication, once stringent controls to eliminate pheromone cues were put in place, no evidence for physical communication of food location could be found. This null result was replicated independently by a different research group on a closely related species, L. neglectus. We conclude that neither L. niger nor L. neglectus foragers communicate resource location using physical contact. Our results increase the burden of proof required for other claims of physical communication of direction in ants, but do not completely rule out this possibility.

Meat ants cut more trail shortcuts when facing long detours

“…The runway towards the maze head was tapered to prevent guidance by pheromone before the ant had to choose a side (figure 5-1) (Popp et al 2017). A sucrose solution droplet (Merck KGaA, Darmstadt, Germany) was presented on a plastic feeder at one side of the T-maze head while a droplet of water was presented on a feeder on the opposite side.…”

Small differences in learning speed for different food qualities can drive efficient collective foraging in ant colonies

“…The runway towards the maze head was tapered to prevent guidance by pheromone before the ant had to choose a side (Fig. 1) (Popp et al 2017). A sucrose solution droplet (Merck KGaA, Darmstadt, Germany) was presented on a plastic feeder at one side of the T-maze head while a droplet of water was presented on a feeder on the opposite side.…”