how does ants communicate

Bottom line. Current evidence suggests that ants communicate through a complex integration of chemical, tactile, and vibrational signals processed via an expanded olfactory receptor repertoire and dynamic neuroanatomical remodeling in the central complex and mushroom bodies.

Olfactory Coding and Pheromonal Signaling

Chemical communication in ants is primarily mediated by an expanded repertoire of odorant receptors (Ors), with some species harboring over 350 intact Or genes (PMID: 22952454). This genomic expansion, particularly within the 9-exon subfamily, is mirrored by a massive increase in antennal lobe glomeruli, which serve as the primary processing units for olfactory information (PMID: 28819196; PMID: 22952454). For example, the worker caste of Camponotus floridanus possesses approximately 454 glomeruli (PMID: 22952454). The function of these receptors is dependent on the highly conserved co-receptor Orco; loss-of-function orco mutations in Ooceraea biroi result in the loss of approximately 82% of antennal lobe glomeruli and a total failure in trail-following and nesting behaviors (PMID: 28802042). While trail-following was historically attributed to single components like (Z)-9-hexadecenal in Linepithema humile, chemical analysis of natural recruitment trails reveals that iridoids such as trans,trans-dolichodial and cis,trans-iridomyrmecin are the primary constituents (PMID: 23028739). These chemical signatures are plastic and can be modified by diet, which subsequently alters nestmate recognition and inter-colony aggression patterns (PMID: 11091966).

Tactile Information Exchange and Trophallaxis

Tactile communication, notably through antennation and trophallaxis, facilitates the exchange of both nutrients and colony-status information. Behavioral evidence in highly social species identifies a population-level lateralization in these contacts; during trophallaxis, the "receiver" ant initiates contact using its right antenna significantly more often than the left, suggesting an asymmetrical neural processing of social cues (PMID: 22483789). While chemical signaling is central to social organization, orco mutants that lack functional odorant receptors still exhibit tactile behaviors such as antennation, indicating these interactions may be mediated by non-olfactory or non-OR dependent sensory pathways (PMID: 28802042).

Vibrational and Acoustic Alarm Mechanisms

Substrate-borne vibrational signaling provides a widespread mode for alarm and defensive coordination. These acoustic signals are often specific to high-threat contexts, such as predator contact, and do not occur during benign encounters with mutualists (PMID: 18480015). In some species, such as Apis cerana, inhibitory vibrational signals are tuned to the fundamental frequency of the threat, effectively stopping recruitment behaviors like the waggle dance to redirect colony focus toward defense (PMID: 27014876).

Multimodal Integration and the Central Complex

Complex behaviors such as navigation and foraging require the integration of olfactory, visual, and tactile inputs. Desert ants (Cataglyphis fortis) demonstrate synergistic benefits from bimodal cues, acquiring landmark information faster and navigating more accurately when both visual and olfactory cues are available (PMID: 21430208). The central complex (CX) of the insect midbrain is a hypothesized neural hub for this coordination. It utilizes a "copy-and-shift" mechanism to translate temporal changes in rotationally invariant sensory valence (such as odor concentration measured in the mushroom bodies) into directional motor commands (PMID: 34882094). This mechanism allows the ant to maintain a current heading until a decrease in sensory valence triggers a turn, effectively facilitating chemotaxis and anemotaxis within a shared global frame of reference (PMID: 34882094).

Neuroanatomical Plasticity in Communication Processing

The ant brain undergoes structural remodeling to accommodate the processing of communicative signals. Long-term avoidance memory formation in leaf-cutting ants is associated with a transient increase in the density of synaptic complexes, or microglomeruli (MG), in the olfactory lip of the mushroom bodies (PMID: 25904854). This remodeling suggests that the formation of new synaptic connections underlies the storage of relevant social or environmental information.

Literature Landscape

Key hub papers provide robust links between the functional specialization of the 9-exon OR subfamily (PMID: 28819196). Important bridging research connects the temporal dynamics of trail pheromones with behavioral response functions (PMID: 22038287).

Evidence Gaps and Limitations

A significant limitation in the current evidence is the technical difficulty of validating odorant receptor (OR) response profiles within endogenous ant neurons. Most functional characterizations rely on heterologous expression in Drosophila or Xenopus oocytes, which may lack ant-specific factors like specialized sensillar architecture or odor-binding proteins that could influence response magnitude (PMID: 28819196). Additionally, while the central complex is modeled as a multimodal integrator, direct physiological evidence for the "copy-and-shift" mechanism in ants remains largely computational (PMID: 34882094). Furthermore, most research into rescue and cooperative behaviors is limited to a small subset of the over 16,000 known ant species, potentially biasing generalizations about the ubiquity of these traits (PMID: 40134390).

Research notebook

What are the chemical structures and functions of pheromones used by ants for trail-following and alarm signaling?

Pheromones and cuticular hydrocarbons (CHCs) are the primary chemical signals in ants, facilitating trail-following, nestmate recognition, and aggregation behaviors through highly specialized odorant receptors (ORs).

Status: verified • Confidence: medium

• Loss-of-function mutations in the odorant receptor co-receptor (orco) in the clonal raider ant Ooceraea biroi result in an inability to follow pheromone trails and participate in typical nesting/aggregation behavior, demonstrating the essential role of OR-mediated olfaction in social coordination. (PMID 28802042, full_text)
• The Argentine ant (Linepithema humile) utilizes (Z)-9-hexadecenal as a primary trail pheromone component, which is critical for food recruitment and collective foraging patterns. (PMID 23028739, abstract)
• Ants possess an expanded repertoire of odorant receptors (ORs) specifically evolved to detect complex cuticular hydrocarbon (CHC) blends that encode colony identity and reproductive status, enabling precise nestmate recognition. (PMID 28819196, abstract)
• Dietary changes can alter the cuticular hydrocarbon profiles of Argentine ants, affecting nestmate recognition and inter-colony aggression, which highlights the plastic nature of chemical signals. (PMID 11091966, abstract)

How do ants use tactile (touch-based) signals, such as antennation, to convey information about food sources or nest mates?

Tactile signals, including antennation and trophallaxis, facilitate nutritional exchange and social bonding, with specific behavioral patterns such as asymmetric antennal contacts.

Status: verified • Confidence: medium

• During trophallaxis in ants, there is a significant asymmetry in antennal contacts, where the receiver ant often initiates more frequent or distinct contacts than the donor, suggesting a role in regulating food flow. (PMID 22483789, abstract)
• While orco mutants lose pheromone-driven social behaviors, they still exhibit tactile interactions such as antennation, indicating that some social interactions are mediated by non-olfactory or non-OR sensory pathways. (PMID 28802042, full_text)

What is the role of acoustic communication (stridulation) in ant colonies, and in what contexts is it employed?

Acoustic communication via substrate-borne vibrations (stridulation) is used by ants for alarm signaling and enhancing coordination with mutualist partners, often increasing ant activity and predator detection.

Status: verified • Confidence: medium

• Ants respond to vibrational alarm signals produced by mutualist treehoppers, which leads to increased ant patrolling and a higher probability of predator discovery, illustrating the role of acoustics in coordinating defensive behaviors. (PMID 18480015, full_text)
• Clonal raider ants (Ooceraea biroi) with loss-of-function orco mutations still exhibit robust alarm responses, suggesting that these behaviors can be triggered by sensory modalities other than olfaction, such as substrate-borne vibrations. (PMID 28802042, full_text)

What are the neurobiological mechanisms in the ant brain that process these communicative signals?

The ant brain processes communicative signals through a highly expanded olfactory system, where the development and maintenance of antennal lobe glomeruli depend on functional odorant receptors and sensory input.

Status: verified • Confidence: medium

• Orco deficiency in Ooceraea biroi leads to the loss of approximately 82% of antennal lobe glomeruli and a significant reduction in olfactory sensory neurons, demonstrating that OR function is required for the neuroanatomical integrity of the ant olfactory system. (PMID 28802042, full_text)
• A specialized clade of odorant receptors in ants is dedicated to detecting cuticular hydrocarbons, with these receptors showing high sensitivity to specific CHC blends. (PMID 28819196, abstract)
• Long-term avoidance memory in leaf-cutting ants is associated with structural plasticity in the mushroom bodies, specifically an increase in the number of synaptic complexes (microglomeruli). (PMID 25904854, abstract)
• Thermal fluctuations experienced during development can increase the number of mushroom body microglomeruli in adult ants, suggesting that sensory environment during development shapes communication processing capacity. (PMID 27147994, abstract)

How do ants integrate multiple sensory modalities (chemical, tactile, acoustic) to achieve complex colony-level behaviors?

Ants integrate multiple sensory modalities, particularly visual landmarks and olfactory cues, to enhance navigation and colony coordination, with the central complex serving as a potential neural hub for this integration.

Status: verified • Confidence: medium

• Desert ants (Cataglyphis fortis) exhibit significantly improved nest-finding performance when both visual and olfactory landmarks are present, indicating that they synergistically integrate multimodal information to navigate back to the nest. (PMID 21430208, abstract)
• Experiments in laboratory mazes confirm that Cataglyphis ants utilize both visual and olfactory cues in a complementary manner, with the presence of both modalities leading to more robust foraging behavior than either alone. (PMID 37614920, abstract)
• The insect central complex is modeled as a neural architecture capable of coordinating multimodal navigation by integrating direction-sensing and landmark-sensing information, facilitating complex spatial behaviors. (PMID 34882094, abstract)

Bottom line. Population-level right-antennal bias during trophallaxis in Formica rufa group ants appears to be driven by asymmetrical olfactory receptor density and side-specific decision rules that facilitate population-wide social coordination.

Population-Level Bias and Evolutionary Coordination

Theoretical game-theoretical analyses indicate that population-level lateralization, where individuals in a group align the direction of their behavioral asymmetries, arises as an evolutionarily stable strategy (ESS) for coordinating behavior between asymmetrical organisms (PMID: 15255105). In the context of the Formica rufa group, this population-level alignment appears to characterize social interactions such as trophallaxis, where the receiver ant uses the right antenna significantly more often than the left (PMID: 22483789).

Sensory Asymmetry and Olfactory Specialization

The neurobiological basis for the right-antennal bias in Formica rufa may be linked to asymmetrical distribution of sensory structures. Preliminary evidence from other Hymenoptera shows the right antenna often possesses a higher density of olfactory receptors (PMID: 22483789). Functional studies in honeybees further support this specialization, showing that the right antenna is more efficient for olfactory learning and the recall of short-term social memories (PMID: 22483789). In social interactions, dyads restricted to using only their right antennae exhibit significantly shorter latencies to first contact and are more likely to engage in positive behaviors, such as proboscis extension, than left-antenna dyads (PMID: 23807465).

Side-Specific Neural Decision Rules

Evidence from ant nestmate recognition tasks suggests that behavioral responses are governed by side-specific decision rules localized in the first-order processing centers (PMID: 20808782). In Camponotus aethiops, familiarization with specific colony odors occurs independently in each brain hemisphere; reducing aggression toward a familiar non-nestmate odor is possible only when that odor is detected by the antenna specifically exposed to it (PMID: 20808782). This lack of bilateral information transfer indicates that the antennal lobes, which have minimal bilateral connectivity, are primary determinants of rapid social recognition and decision-making (PMID: 20808782).

Molecular and Neurochemical Drivers of Sociability

The underlying motivation for trophallaxis-based interactions is modulated by complex neurochemical and genetic factors. In honeybees, genome-wide association studies link trophallaxis frequency to variants in genes such as neuroligin-2 (nlg2) and NMDA receptor 2, which are localized to higher-order centers like the mushroom body Kenyon cells (PMID: 40956789). Furthermore, dopamine signaling is a critical driver of social motivation; microinjection of dopamine significantly increases sociability and the likelihood of interaction with conspecifics (PMID: 30359390). In contrast, high levels of octopamine can override these signals and block dyadic interactions, suggesting that biogenic amine titers tune the propensity for the lateralized contacts observed in social insects (PMID: 30359390).

Evidence Gaps and Limitations

The specific neurobiological drivers for Formica rufa group lateralization remain partially inferred from other Hymenoptera, such as honeybees and Camponotus species. Direct neuroanatomical mapping of olfactory receptor density specifically in the Formica rufa group is not reported in the available evidence. Additionally, while side-specific processing is established for nestmate recognition, its direct causal role in regulating food flow during trophallaxis in this specific group has not been fully elucidated.

Research notebook

What are the chemical structures and functions of pheromones used by ants for trail-following and alarm signaling?

Pheromones and cuticular hydrocarbons (CHCs) are the primary chemical signals in ants, facilitating trail-following, nestmate recognition, and aggregation behaviors through highly specialized odorant receptors (ORs).

Status: verified • Confidence: medium

• Loss-of-function mutations in the odorant receptor co-receptor (orco) in the clonal raider ant Ooceraea biroi result in an inability to follow pheromone trails and participate in typical nesting/aggregation behavior, demonstrating the essential role of OR-mediated olfaction in social coordination. (PMID 28802042, full_text)
• The Argentine ant (Linepithema humile) utilizes (Z)-9-hexadecenal as a primary trail pheromone component, which is critical for food recruitment and collective foraging patterns. (PMID 23028739, abstract)
• Ants possess an expanded repertoire of odorant receptors (ORs) specifically evolved to detect complex cuticular hydrocarbon (CHC) blends that encode colony identity and reproductive status, enabling precise nestmate recognition. (PMID 28819196, abstract)
• Dietary changes can alter the cuticular hydrocarbon profiles of Argentine ants, affecting nestmate recognition and inter-colony aggression, which highlights the plastic nature of chemical signals. (PMID 11091966, abstract)

How do ants use tactile (touch-based) signals, such as antennation, to convey information about food sources or nest mates?

Tactile signals, including antennation and trophallaxis, facilitate nutritional exchange and social bonding, with specific behavioral patterns such as asymmetric antennal contacts.

Status: verified • Confidence: medium

• During trophallaxis in ants, there is a significant asymmetry in antennal contacts, where the receiver ant often initiates more frequent or distinct contacts than the donor, suggesting a role in regulating food flow. (PMID 22483789, abstract)
• While orco mutants lose pheromone-driven social behaviors, they still exhibit tactile interactions such as antennation, indicating that some social interactions are mediated by non-olfactory or non-OR sensory pathways. (PMID 28802042, full_text)

What is the role of acoustic communication (stridulation) in ant colonies, and in what contexts is it employed?

Acoustic communication via substrate-borne vibrations (stridulation) is used by ants for alarm signaling and enhancing coordination with mutualist partners, often increasing ant activity and predator detection.

Status: verified • Confidence: medium

• Ants respond to vibrational alarm signals produced by mutualist treehoppers, which leads to increased ant patrolling and a higher probability of predator discovery, illustrating the role of acoustics in coordinating defensive behaviors. (PMID 18480015, full_text)
• Clonal raider ants (Ooceraea biroi) with loss-of-function orco mutations still exhibit robust alarm responses, suggesting that these behaviors can be triggered by sensory modalities other than olfaction, such as substrate-borne vibrations. (PMID 28802042, full_text)

What are the neurobiological mechanisms in the ant brain that process these communicative signals?

The ant brain processes communicative signals through a highly expanded olfactory system, where the development and maintenance of antennal lobe glomeruli depend on functional odorant receptors and sensory input.

Status: verified • Confidence: medium

• Orco deficiency in Ooceraea biroi leads to the loss of approximately 82% of antennal lobe glomeruli and a significant reduction in olfactory sensory neurons, demonstrating that OR function is required for the neuroanatomical integrity of the ant olfactory system. (PMID 28802042, full_text)
• A specialized clade of odorant receptors in ants is dedicated to detecting cuticular hydrocarbons, with these receptors showing high sensitivity to specific CHC blends. (PMID 28819196, abstract)
• Long-term avoidance memory in leaf-cutting ants is associated with structural plasticity in the mushroom bodies, specifically an increase in the number of synaptic complexes (microglomeruli). (PMID 25904854, abstract)
• Thermal fluctuations experienced during development can increase the number of mushroom body microglomeruli in adult ants, suggesting that sensory environment during development shapes communication processing capacity. (PMID 27147994, abstract)

How do ants integrate multiple sensory modalities (chemical, tactile, acoustic) to achieve complex colony-level behaviors?

Ants integrate multiple sensory modalities, particularly visual landmarks and olfactory cues, to enhance navigation and colony coordination, with the central complex serving as a potential neural hub for this integration.

Status: verified • Confidence: medium

• Desert ants (Cataglyphis fortis) exhibit significantly improved nest-finding performance when both visual and olfactory landmarks are present, indicating that they synergistically integrate multimodal information to navigate back to the nest. (PMID 21430208, abstract)
• Experiments in laboratory mazes confirm that Cataglyphis ants utilize both visual and olfactory cues in a complementary manner, with the presence of both modalities leading to more robust foraging behavior than either alone. (PMID 37614920, abstract)
• The insect central complex is modeled as a neural architecture capable of coordinating multimodal navigation by integrating direction-sensing and landmark-sensing information, facilitating complex spatial behaviors. (PMID 34882094, abstract)

Mapped from the sources already gathered in this chat. Links reflect what the cited papers report, not exhaustive pathway coverage.

Bottom line. Current evidence indicates that sensory enrichment in Acromyrmex ambiguus triggers synaptic pruning via competitive projection neuron refinement, while avoidance learning promotes a transient synaptogenesis followed by network reorganization to preserve memory traces.

Divergent Plasticity in Mushroom Body Microglomeruli

In the leaf-cutting ant Acromyrmex ambiguus, structural remodeling of the mushroom body (MB) calyces is modality-specific and context-dependent, occurring primarily in the non-dense (ND) olfactory lip (PMID: 25904854) «✓ PMID:25904854». Sensory enrichment through the simultaneous collection of multiple non-harmful plant species leads to a significant ~20% reduction in synapsin-immunoreactive (IR) bouton densities within 3 days, indicating net synaptic pruning (PMID: 25904854) «✓ PMID:25904854». In contrast, the formation of long-term avoidance memory (LTAM)—triggered by plant substrates harmful to the symbiotic fungus—induces a transient ~25% increase in microglomeruli (MG) density two days post-learning (PMID: 25904854) «✓ PMID:25904854». These variations occur independently of changes in neuropil volume, suggesting that the dynamics reflect the addition or elimination of individual synaptic complexes rather than volumetric scaling (PMID: 25904854; PMID: 27147994) «✓ PMID:25904854» «✓ PMID:27147994».

Mechanism of Sensory Exposure-Induced Pruning

Sensory exposure to a high diversity of odorants from multiple plant species is hypothesized to increase competition among activated olfactory projection neurons (PNs) (PMID: 25904854) «✓ PMID:25904854». This competitive refinement process results in the elimination of less-used MGs, effectively pruning the PN boutons in the MB lip (PMID: 25904854) «✓ PMID:25904854». This phenomenon mirrors visual sensory pruning observed in the MB collar of other Hymenoptera following light exposure (PMID: 25904854) «✓ PMID:25904854». In A. ambiguus, this reorganization may optimize the olfactory circuit, preparing the MB microcircuits for subsequent associative learning by narrowing the response spectrum (PMID: 25904854) «✓ PMID:25904854».

Temporal Dynamics of Avoidance Memory Reorganization

The synaptogenesis associated with LTAM is short-lived; while MG density peaks two days after the incorporation of fungicide-treated leaves, it returns to baseline levels by day 15, even as behavioral avoidance persists (PMID: 25904854) «✓ PMID:25904854». The proposed mechanism involves an initial growth phase of new, novel associative MG connections followed by the competitive elimination of existing, less-used complexes (PMID: 25904854) «✓ PMID:25904854». This sequence results in a reorganized associative network that preserves the memory trace without a permanent increase in energetic costs or physical space (PMID: 25904854) «✓ PMID:25904854». Such transient increases in MG density have also been observed in honeybee olfactory LTAM, suggesting a conserved mechanism for information storage in social insect brains (PMID: 25904854; PMID: 27147994) «✓ PMID:25904854» «✓ PMID:27147994».

Modality Specificity and Environmental Regulation

Structural remodeling during avoidance learning is restricted to olfactory regions; synapsin-IR bouton densities in the visual collar remain stable throughout the 15-day learning period (PMID: 25904854) «✓ PMID:25904854». This specificity confirms that the changes are driven by olfactory-gustatory associations within the fungus garden rather than systemic effects (PMID: 25904854) «✓ PMID:25904854». Furthermore, the baseline capacity for this remodeling is shaped during development; in Camponotus mus, daily thermal fluctuations (amplitude 3.3°C) mimicking nurse-tending behavior maximize the initial number of adult MGs in the ND lip, potentially providing greater computational capacity for subsequent adult plasticity (PMID: 27147994) «✓ PMID:27147994».

Research notebook

What are the chemical structures and functions of pheromones used by ants for trail-following and alarm signaling?

Pheromones and cuticular hydrocarbons (CHCs) are the primary chemical signals in ants, facilitating trail-following, nestmate recognition, and aggregation behaviors through highly specialized odorant receptors (ORs).

Status: verified • Confidence: medium

• Loss-of-function mutations in the odorant receptor co-receptor (orco) in the clonal raider ant Ooceraea biroi result in an inability to follow pheromone trails and participate in typical nesting/aggregation behavior, demonstrating the essential role of OR-mediated olfaction in social coordination. (PMID 28802042, full_text)
• The Argentine ant (Linepithema humile) utilizes (Z)-9-hexadecenal as a primary trail pheromone component, which is critical for food recruitment and collective foraging patterns. (PMID 23028739, abstract)
• Ants possess an expanded repertoire of odorant receptors (ORs) specifically evolved to detect complex cuticular hydrocarbon (CHC) blends that encode colony identity and reproductive status, enabling precise nestmate recognition. (PMID 28819196, abstract)
• Dietary changes can alter the cuticular hydrocarbon profiles of Argentine ants, affecting nestmate recognition and inter-colony aggression, which highlights the plastic nature of chemical signals. (PMID 11091966, abstract)

How do ants use tactile (touch-based) signals, such as antennation, to convey information about food sources or nest mates?

Tactile signals, including antennation and trophallaxis, facilitate nutritional exchange and social bonding, with specific behavioral patterns such as asymmetric antennal contacts.

Status: verified • Confidence: medium

• During trophallaxis in ants, there is a significant asymmetry in antennal contacts, where the receiver ant often initiates more frequent or distinct contacts than the donor, suggesting a role in regulating food flow. (PMID 22483789, abstract)
• While orco mutants lose pheromone-driven social behaviors, they still exhibit tactile interactions such as antennation, indicating that some social interactions are mediated by non-olfactory or non-OR sensory pathways. (PMID 28802042, full_text)

What is the role of acoustic communication (stridulation) in ant colonies, and in what contexts is it employed?

Acoustic communication via substrate-borne vibrations (stridulation) is used by ants for alarm signaling and enhancing coordination with mutualist partners, often increasing ant activity and predator detection.

Status: verified • Confidence: medium

• Ants respond to vibrational alarm signals produced by mutualist treehoppers, which leads to increased ant patrolling and a higher probability of predator discovery, illustrating the role of acoustics in coordinating defensive behaviors. (PMID 18480015, full_text)
• Clonal raider ants (Ooceraea biroi) with loss-of-function orco mutations still exhibit robust alarm responses, suggesting that these behaviors can be triggered by sensory modalities other than olfaction, such as substrate-borne vibrations. (PMID 28802042, full_text)

What are the neurobiological mechanisms in the ant brain that process these communicative signals?

The ant brain processes communicative signals through a highly expanded olfactory system, where the development and maintenance of antennal lobe glomeruli depend on functional odorant receptors and sensory input.

Status: verified • Confidence: medium

• Orco deficiency in Ooceraea biroi leads to the loss of approximately 82% of antennal lobe glomeruli and a significant reduction in olfactory sensory neurons, demonstrating that OR function is required for the neuroanatomical integrity of the ant olfactory system. (PMID 28802042, full_text)
• A specialized clade of odorant receptors in ants is dedicated to detecting cuticular hydrocarbons, with these receptors showing high sensitivity to specific CHC blends. (PMID 28819196, abstract)
• Long-term avoidance memory in leaf-cutting ants is associated with structural plasticity in the mushroom bodies, specifically an increase in the number of synaptic complexes (microglomeruli). (PMID 25904854, abstract)
• Thermal fluctuations experienced during development can increase the number of mushroom body microglomeruli in adult ants, suggesting that sensory environment during development shapes communication processing capacity. (PMID 27147994, abstract)

How do ants integrate multiple sensory modalities (chemical, tactile, acoustic) to achieve complex colony-level behaviors?

Ants integrate multiple sensory modalities, particularly visual landmarks and olfactory cues, to enhance navigation and colony coordination, with the central complex serving as a potential neural hub for this integration.

Status: verified • Confidence: medium

• Desert ants (Cataglyphis fortis) exhibit significantly improved nest-finding performance when both visual and olfactory landmarks are present, indicating that they synergistically integrate multimodal information to navigate back to the nest. (PMID 21430208, abstract)
• Experiments in laboratory mazes confirm that Cataglyphis ants utilize both visual and olfactory cues in a complementary manner, with the presence of both modalities leading to more robust foraging behavior than either alone. (PMID 37614920, abstract)
• The insect central complex is modeled as a neural architecture capable of coordinating multimodal navigation by integrating direction-sensing and landmark-sensing information, facilitating complex spatial behaviors. (PMID 34882094, abstract)

What are the neurobiological mechanisms in the ant brain that process these communicative signals?

In Acromyrmex ambiguus, sensory exposure to multiple novel plant odors induces synaptic pruning (a ~20% decrease in microglomeruli density) in the olfactory lip of the mushroom bodies, whereas long-term avoidance memory formation triggers a transient (~25%) increase in microglomeruli density followed by network reorganization.

Status: verified • Confidence: medium

• Foraging on 10 different plant species over three days led to a ~20% reduction in synapsin-immunoreactive bouton density in the non-dense lip of the mushroom body, suggesting that enriched sensory exposure alone promotes synaptic pruning. (PMID 25904854, results)
• In contrast, forming a long-term avoidance memory by associating a plant with fungal toxicity caused a significant 25% increase in microglomeruli density in the olfactory lip after two days, which returned to baseline levels by day 15. (PMID 25904854, results)
• The authors hypothesize that the transient increase during learning reflects the formation of new synaptic connections, followed by the elimination of less-used microglomeruli to maintain stable density while preserving the memory trace. (PMID 25904854, discussion)