knowledgeable ants do not transfer information about the direction of a food source to naive, outgoing ants
For my Bachelor’s thesis, I worked with Dr. Tomer Czaczkes (Univ. Regensburg) on the question whether ants who are on their way back to the nest from a food source can tell outgoing, naive ants, whether to go left or right at a fork in the way. After carefully providing the best circumstances for this to happen, we concluded that Lasius niger ants do not possess this ability. However, to solidify this null result, we collaborated with Dr. Elva Robinson and Dr. Philipp Buckham-Bonnet, at the University of York, to repeat the experiment in a different lab with a slightly different setup, and a closely related species (Lasius neglectus). We combined these two datasets with that of a very similar study by Dr. Sophie E. F. Evison to conclude with high certainty that this type of ant does not convey directional information to naive ants on a foraging trail via physical contact. (Popp et al., 2018)
Left: Study species at a feeder, marked with paint (credit Tomer Czaczkes), Middle: illustration of the setup, Right: results (no effect of the interaction with the knowledgeable ant)
References
2018
No evidence for tactile communication of direction in foraging Lasius ants
S. Popp , P. Buckham-Bonnett , S. E. F. Evison , and 2 more authors
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.
