It has been known for centuries that floral and extra-floral nectar secreted by plants attracts and rewards animals. Extra-floral nectar is involved in so-called indirect defense by attracting animals (generally ants) that prey on herbivores, or by discouraging herbivores from feeding on the plant. Floral nectar is presented inside the flower close to the reproductive organs and rewards animals that perform pollination while visiting the flower. In both cases nectar is a source of carbon and nitrogen compounds that feed animals, the most abundant solutes being sugars and amino acids. Plant–animal relationships involving the two types of nectar have therefore been used for a long time as text-book examples of symmetric mutualism: services provided by animals to plants in exchange for food provided by plants to animals. Cheating (or deception or exploitation), namely obtaining the reward/service without returning any counterpart, is however, well-known in mutualistic relationships, since the interacting partners have conflicting interests and selection may favor cheating strategies. A more subtle way of exploiting mutualism was recently highlighted. It implies the evolution of strategies to maximize the benefits obtained by one partner while still providing the reward/service to the other partner. Several substances other than sugars and amino acids have been found in nectar and some affect the foraging behavior of insects and potentially increase the benefits to the plant. Such substances can be considered plant cues to exploit mutualism. Recent evidence motivated some authors to use the term “manipulation” of animals by plants in nectar-mediated mutualistic relationships. This review highlights the recent background of the “manipulation” hypothesis, discussing it in the framework of new ecological and evolutionary scenarios in plant–animal interactions, as a stimulus for future research.

Citizen science can generate data that would not exist otherwise while increasing public scientific literacy. However, the quality and use of citizen science data have been criticized in the recent ecological literature. We need an approach that advances eco‐evolutionary understanding, achieves education goals and incorporates public participation into as many aspects of the scientific process as possible. We collaborated with public participants to make new discoveries about the distribution and ecology of ants while informing the next studies that participants and scientists might perform together. We implemented the School of Ants (SoA) program in which participants sample ants that are identified by taxonomic experts. Using a comprehensive framework that meets the needs of multiple agents, we also developed outreach materials about ant biology, collaborated with educators to incorporate SoA into classroom science, and launched an international SoA module in Italy. In the first 17 months, SoA volunteers collected ants at 500 unique sites across the USA‐including all 50 states and Washington, D.C. To address concerns about the validity of citizen scientist‐derived data, we conducted a ground truthing trial that confirmed that trained and untrained volunteers were equally effective at collecting ants. Data from SoA samples indicate that ant diversity varies across wide geographic scales and that there can be high levels of native ant diversity where people live. SoA volunteers collected 7 exotic and 107 native ant species. Although exotic ants were common, ants native to North America occurred in ∼70% of all sites. Many of the ants common in backyards were species that tend to be very poorly studied. For example, citizen scientists documented a range extension of more than 2000 miles for the Asian Needle Ant, Pachycondyla chinensis. Using SoA data as a starting point, we collaborated with a science writer to produce a free, interactive iBook about the common ants in North America; the book included distribution maps such as that for P. chinensis informed by participant collections. Moving forward, we plan to leverage this existing framework to address more complex ecological and evolutionary questions in partnership with our public participants.

Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk.

Plant–ant interactions are generally considered as mutualisms, with both parties gaining benefits from the association. It has recently emerged that some of these mutualistic associations have, however, evolved towards other forms of relationships and, in particular, that plants may manipulate their partner ants to make reciprocation more beneficial, thereby stabilizing the mutualism. Focusing on plants bearing extrafloral nectaries, we review recent studies and address three key questions: (i) how can plants attract potential partners and maintain their services; (ii) are there compounds in extrafloral nectar that could mediate partner manipulation; and (iii) are ants susceptible to such compounds? After reviewing the current knowledge on plant–ant associations, we propose a possible scenario where plant-derived chemicals, such as secondary metabolites, known to have an impact on animal brain, could have evolved in plants to attract and manipulate ant behaviour. This new viewpoint would place plant–animal interaction in a different ecological context, opening new ecological and neurobiological perspectives of drug seeking and use.

This research represents the first description of stridulations produced by the different castes (gynes, males, workers) of the harvesting ants Messor minor and M. wasmanni. Further information on the stridulatory, sounds produced by M. capitatus and M. structor are also given; The sounds produced by the examined samples (n = 103) of the genus Messor are homogenous in their acoustic structure and consist of long sequences of pulse‐trains organized in two subunits. They are characterized by pulses with opposite phase produced by rapidly raising and lowering the gaster, so as to cause a series of ridges to rub against a scraper. For all samples of the tested species, the maximum frequency values lie within the ultrasonic range (> 18–20 kHz) and vary between 41 and 98 kHz. This is the first recording of ultrasounds produced by ants of the genus Messor. Hence, the range of frequencies involved in sound production by these species is considerably wider than previously known. Moreover, the description and comparison of several acoustical parameters show some caste‐dependent differences and similarities among the examined samples. The possible functional role of stridulations emitted by the different castes of these species is also discussed.