Evidence for Mushroom Intelligence
For centuries, fungi have occupied a mysterious corner of the natural world. Neither plant nor animal, these organisms have long confounded classification and spurred scientific inquiry with their unique biology and seemingly magical capacities—most notably, the transformation of organic matter into new life. From the gilled mushrooms dotting a forest floor to the mold quietly working on a loaf of bread, fungi are everywhere. Their roles in decomposition, nutrient cycling, and symbiosis with plants paint them as essential players in Earth’s ecosystems. Yet, it is only in recent decades that a provocative question has arisen: Could fungi exhibit forms of intelligence or, at the very least, an advanced capacity to process information about their environment?
The term “mushroom intelligence” or “the fungal mind” might strike many as whimsical or pseudoscientific. After all, intelligence is most commonly associated with animals, particularly those with brains. The concept of a “mind” frequently implies centralized cognition, consciousness, and the capacity for subjective experience—traits we would think are impossible to find in an organism lacking a neural network. Nevertheless, a growing body of research suggests that fungi, in particular their filamentous networks known as mycelia, display complex behaviour, responsiveness to environmental cues, and a seemingly purposeful allocation of resources.
One major line of evidence for fungal intelligence stems from the resilience and adaptability of mycelial networks. Mycelia can dynamically reallocate growth to exploit new resources, circumvent obstacles, and optimize their foraging strategies. Researchers have observed that some fungal networks can recover from damage in ways that resemble problem-solving tactics. Additional clues come from recent experiments showing that certain mushrooms, when probed with electrodes, display electrical spiking activity—patterns reminiscent of nerve impulses in animals. These electrical oscillations may help fungi coordinate resource distribution, stress responses, and other essential functions.
Other lines of inquiry into “the fungal mind” intersect with the broader study of distributed cognition—the idea that intelligence and problem-solving can exist in decentralized systems lacking a central controlling organ. Organisms like slime molds (which, despite the name, are not actually fungi) have famously demonstrated “brainless” problem-solving abilities, such as finding the most efficient route through a maze or replicating the railway networks of major cities. Although fungi are evolutionarily distinct from slime molds, these examples suggest that complex information processing can occur in unexpected places and forms.
In this long-form article, we will embark on a comprehensive exploration of the emerging research and theories surrounding fungal intelligence. We will discuss fungal biology and mycelial structure, examine how intelligence is defined across the biological spectrum, and analyze experimental evidence that points to the remarkable adaptability of mushrooms and their underground networks. We will also explore the philosophical and ethical implications of attributing “intelligence” to organisms that traditionally have not been considered sentient or mindful. By the end of this investigation, we hope to give you a deeper appreciation for the hidden complexity of the fungal kingdom—and perhaps open your mind to the possibility that intelligence is far more widespread, subtle, and evolutionary ancient than previously believed.
Fungal Biology the Foundations of a Hidden Kingdom
What Are Fungi?
Fungi belong to their own biological kingdom, separate from plants, animals, protists, and bacteria. Once considered a subset of plants, fungi have since been recognized as evolutionarily closer to animals than to plants. The key distinctions are manifold: fungi have cell walls primarily composed of chitin (rather than cellulose in plants), they lack the ability to photosynthesize, and they obtain nutrients through absorption rather than ingestion. This absorptive nutrition is a cornerstone of fungal ecology, as it allows them to decompose a wide range of organic materials, turning dead matter into life-sustaining compounds for themselves and other organisms.
With an estimated 2.2 to 3.8 million species worldwide, fungi are incredibly diverse. They range from microscopic yeast cells used in bread and beer production to large bracket fungi clinging to tree trunks, and from the humble button mushrooms grown for food to the luminous glow-in-the-dark fungal species found in tropical forests. Yet, across this diversity, one trait remains nearly universal the presence of mycelium.
The Structure of Mycelium
The term “mycelium” refers to the network of filamentous threads called hyphae. These hyphae grow by extending their tips into new substrates, secreting enzymes, and absorbing the resulting digested nutrients. The combined mass of hyphae can spread extensively, even covering kilometres of soil or decaying wood. Often, the mushroom or fruiting body we see above ground represents only a tiny fraction of the entire organism—akin to the tip of an iceberg. This wide-reaching network below ground is one reason fungi can play large-scale roles in nutrient cycling and ecological communication.
Structurally, hyphae are composed of tubular cells connected end to end, divided by porous cross walls called septa (in septate fungi) or lacking such divisions (in coenocytic fungi). These pores can be quite large, permitting the flow of cytoplasm, organelles, and even nuclei throughout the fungal network. This cytoplasmic streaming is vital for distributing nutrients and signalling molecules across distant parts of the mycelium. One could argue that this internal fluid connectivity forms the basis for a form of “intra-fungal communication” that is reminiscent of circulatory systems in animals—though it is not driven by a heart or central pump.
Hyphal Growth and Adaptations
Fungi thrive in a staggering array of environments, from scorching deserts to deep-sea vents. This success can be partly attributed to the adaptability of hyphal growth. When encountering inhospitable areas, hyphae can adjust their growth rate or direction, re-route resources from older, less productive sections of the mycelium, and even produce specialized structures that help them anchor in tough substrates.
For example, rhizomorphs, thick rope-like bundles of hyphae, can extend rapidly across barren ground or dead wood, acting as fungal “highways” for resource transport. Moreover, certain parasitic fungi form haustoria, specialized hyphal tips that penetrate host cells to extract nutrients. These varied adaptations underscore how mycelial networks exhibit flexible and responsive foraging strategies—features that some researchers interpret as early hallmarks of intelligence.
Mycorrhizal Networks in Symbiosis and Communication
Mycorrhiza refers to the symbiotic association between fungi and plant roots. In these mutualistic relationships, fungi colonize a plant’s root system and extend their mycelium into the surrounding soil, increasing the plant’s access to water, phosphorus, and other nutrients. In return, the plant provides carbohydrates and other organic compounds produced via photosynthesis. This mycorrhizal network can connect multiple plants, sometimes even across different species, forming what researchers colloquially refer to as the “wood wide web.”
Research over the past few decades has shown that these interconnecting networks facilitate more than mere nutrient exchange. They can transmit chemical signals warning of pest attacks, share carbon among plants, and possibly coordinate growth or reproductive efforts. In some cases, “mother trees” have been found to shuttle resources to seedlings via fungal intermediaries. These examples of resource sharing, communication, and cooperation challenge the notion of mindless competition in nature.
The existence of large-scale, cooperative underground networks has prompted some to speculate that the mycelial network functions as a super organism with emergent properties that could be analogous to cognition. Although this idea remains controversial, its growing prominence in scientific discourse sets the stage for more in-depth investigation of fungal intelligence.
Defining Intelligence in the Biological Context
Traditional Views of Intelligence
For much of scientific history, intelligence was thought to be the province of animals with complex nervous systems. Researchers focused on brains and central nervous systems (CNS) as the seat of cognition, memory, and learning. Under this paradigm, intelligence required an organized cluster of neurons capable of signal processing, integration, and decision-making. By this yardstick, plants, and fungi—lacking neurons—would be considered devoid of intelligence or mental processes.
However, the emergence of neurobiology as a field in the late 19th century and the subsequent rise of cognitive science in the 20th century led to fresh perspectives on what intelligence means. Where once “intelligence” was virtually synonymous with “human cognition,” it now includes a broader spectrum of problem-solving and adaptive behaviour in both humans and non-human species.
Expanding the Concept of Cognition
Modern definitions of cognition emphasize information processing—the ability of an organism to acquire, store, transform, and use information from its environment to guide behaviour. By this measure, many forms of life display rudimentary cognitive traits. Plants exhibit tropic responses, memory (e.g., the Venus flytrap’s short-term memory for prey capture), and signals that coordinate complex defensive strategies. Slime molds (again, technically protists rather than fungi) famously solve mazes and optimize resource networks without a single neuron.
Such examples have led to the broader concept of “mindless mastery,” wherein distributed, decentralized networks can produce behaviour that appears intelligent—if we define intelligence primarily as effective problem-solving. Consequently, the question shifts from “Does it have a brain?” to “Does it process information, and how effectively?” This approach has opened scientific inquiry into mushrooms, which appear to manage resources, communicate, and respond to stressors in ways reminiscent of purposeful, directed action.
Distributed and Decentralized Intelligence
Distributed cognition refers to cognitive processes that do not rely on a single centralized organ. Examples span entire insect colonies, computer networks modeled on neural architectures, and yes, even the branching threads of mycelial networks. In the fungal realm, intelligence may thus be more akin to a “swarm intelligence,” where individual parts (hyphae) work in concert through local interactions, leading to emergent global coordination.
This concept resonates with a shift in philosophy of mind away from strict anthropocentrism toward a more inclusive perspective that acknowledges different levels and forms of cognition across life forms. If an entity can sense changes in its environment, integrate those signals, and adapt or optimize its behaviour, many researchers argue that it may be considered, in some sense, “intelligent.”
The Fungal Mind Hypothesis
Historical Perspectives
Throughout human history, mushrooms, and fungi have carried an air of mystery. Pre-scientific cultures often ascribed spiritual significance to mushrooms, viewing them as messengers from an unseen realm or even as direct conduits to spiritual experiences (as in the use of certain psychedelic mushrooms in shamanic rituals). While these beliefs were not framed in the language of modern science, they hinted at a sense that fungi occupy a unique ecological and existential niche.
Once the scientific revolution and Enlightenment philosophies took hold in the 17th and 18th centuries, supernatural explanations for fungal behaviour were largely dismissed. Fungi were relegated to the realm of curiosity or pathology, studied primarily for their role in disease, spoilage, or fermentation. The idea that mushrooms could possess any form of intelligence was far outside the mainstream.
Recent Interest and Novel Research
Interest in fungal networks as potential analogues of intelligent systems soared in the late 20th century, motivated by several developments:
The discovery of extensive mycelial networks in forests, suggesting complex interactions among trees, fungi, and other organisms.
Breakthroughs in computational theory, particularly around distributed systems and neural networks, which offered conceptual frameworks for rethinking cognition in non-human systems.
Increasing recognition of slime mold intelligence, prompting scientists to ask if similar problem-solving capacities exist in other decentralized life forms.
Recently, researchers like Dr. Andrew Adamatzky have explored the electrical properties of mushrooms, measuring spiking patterns akin to neural impulses. Others, such as ecologist Suzanne Simard, have extensively documented the “wood wide web,” illustrating how forest ecosystems might function as integrated networks supported by fungi. These and other scientists are reviving questions that once seemed unscientific: Could mycelia “think,” plan, or remember?
Interdisciplinary Approaches
Because the question of fungal intelligence cuts across multiple domains—from ecology and evolutionary biology to computer science and philosophy—it demands interdisciplinary collaboration. We find:
Ecologists studying resource flows and population dynamics.
Mycologists investigating fungal physiology.
Physicists and computer scientists analyzing electrical signals and modeling the mycelium as a complex adaptive system.
Philosophers and cognitive scientists debating the ontological status of fungal behaviour.
This synergy is gradually unpacking the notion of a “fungal mind,” framing it less as a fringe idea and more as a valid scientific hypothesis ripe for empirical study.
Evidence for Fungal Intelligence
Problem-Solving and Resource Allocation
One of the most compelling arguments for fungal intelligence lies in their problem-solving capabilities. Field studies indicate that fungi can distribute their hyphae in patterns that maximize nutrient uptake and minimize redundancy, effectively optimizing resource foraging. In controlled laboratory conditions, a mycelial colony can navigate physical obstacles to reach a nutrient source, re-routing its growth if a path is blocked.
This dynamic resource reallocation is not merely a passive process. When a nutrient-rich patch is discovered, certain sections of the mycelial network redirect growth, allocate more metabolic energy to that region, and may even reduce the flow of resources to less productive areas. Such optimal foraging strategies require the organism to sense local conditions, communicate that information across the network, and coordinate a global response—hallmarks of an intelligent system in many definitions.
Signal Transmission and Electrical Oscillations
The idea that mushrooms or their mycelia produce electrical signals has gained significant traction. In the last couple of decades, researchers have applied electrodes to various mushroom species—such as Pleurotus djamor, the pink oyster mushroom—and recorded spiking events that resemble the action potentials in animal neurons. The rate, amplitude, and frequency of these spikes can change in response to environmental conditions, mechanical stimuli, or chemical signals.
While the physiological basis for these impulses is still under study, one hypothesis is that ion fluxes along the cell membrane cause rapid changes in membrane potential—an electrical spike. These spikes may function as a form of communication, allowing distant parts of the mycelial network to coordinate growth, respond to threats, or manage resources. Some mushrooms even exhibit quasi-regular oscillatory patterns, hinting that these signals could serve as internal “clocks” or pacemakers, akin to circadian rhythms in plants and animals.
Response to Environmental Stimuli
Fungi respond robustly to changes in humidity, temperature, pH, and the presence of other organisms. Beyond the obvious morphological changes (e.g., sporulation triggered by environmental stress), there is emerging evidence that mycelia can “remember” previous stress episodes and react more efficiently if faced with the same challenge again—a rudimentary form of learning or adaptive memory. Certain fungal species produce specialized chemical compounds in response to predators or competing microbes, adjusting the intensity and types of these secretions based on past encounters.
Learning and Memory in Networks?
While the notion of a mushroom “learning” evokes skepticism, it aligns with the principle that any adaptive biological system can encode information about experiences to optimize future behaviour. In computational models, a mycelium’s capacity to alter growth patterns or electrical signals in a way that persists even after the initial stimulus is removed suggests a memory-like state. These states are not “memories” in the neurological sense but do serve a functionally equivalent role, guiding subsequent responses.
Thus, the accumulation of empirical findings indicates that mushrooms and their mycelial networks demonstrate environmental responsiveness, adaptive resource allocation, electrical signaling, and possible memory effects—all potential components of an intelligence-like mechanism.
Communication Mechanisms in Fungi
Chemical Signaling and Semiochemicals
Fungi are biochemical powerhouses. They produce a vast array of secondary metabolites, including antibiotics (e.g., penicillin from Penicillium rubens), toxins (e.g., aflatoxins from Aspergillus species), and various signaling molecules that influence both fungal and plant physiology. These compounds can act as semiochemicals, transmitting information from one fungus to another or from fungi to plants and insects.
For instance, when a section of mycelium detects a pathogen, it can release warning molecules that trigger defence mechanisms in neighbouring areas. Similar signaling may govern the transition from vegetative growth to sporulation, coordinating the entire colony to shift strategies when resources are depleted or environmental conditions worsen.
Electrical Signals and Impulse Conduction
As noted, fungal hyphae exhibit electrical potentials that propagate in ways akin to nerve impulses in animals. While the conduction velocity and underlying ionic mechanisms might differ, the basic principle remains: a localized change in membrane potential can rapidly travel across the fungal network. This property is pivotal for synchronous activities, such as the coordinated release of enzymes or the collective redirection of growth.
Moreover, the existence of spike trains—series of repeated electrical impulses—leads some researchers to draw analogies to neuronal coding in animal brains. Although it is premature to claim that fungi “think” in the sense that humans do, these signals open the door to a more nuanced understanding of fungal communication and decision-making.
Hydraulic and Turgor-Pressure Signaling
A lesser-discussed but significant mode of information transfer in fungi is hydraulic signaling. Because fungal cells maintain high internal turgor pressure, changes in fluid pressure can propagate through the network, influencing hyphal extension and nutrient transport. This phenomenon can be likened to a “pressure wave” traveling through interconnected hyphae, potentially carrying information about localized conditions (e.g., dryness, mechanical stress, or chemical gradients).
The “Wood Wide Web” Plant–Fungi–Plant Communication
The most visible aspect of fungal communication may be their role in mediating information between plants. Through mycorrhizal networks, fungi enable plants to communicate about pests, share carbon, and even manipulate root growth. Experiments have demonstrated that a plant under aphid attack can send warning signals via mycorrhizal connections, prompting neighboring plants to ramp up their chemical defenses. This interspecies communication raises fascinating questions about the emergence of ecosystem intelligence, where multiple species cooperate through complex feedback loops maintained by fungal networks.
Case Studies and Experiments
Spiking Behaviour in Mushrooms (Adamatzky’s Research)
One groundbreaking line of inquiry comes from the work of Andrew Adamatzky at the University of the West of England. By applying electrodes to various mushroom caps and measuring electrical potentials over time, Adamatzky documented pulses ranging from 0.5 to 2.6 mV with frequencies around 0.03 to 2 spiking events per minute—highly reminiscent of neuronal action potentials. In some species, these pulses changed in response to mechanical damage or exposure to light, implying an active role in environmental sensing.
Mycelial Maze-Solving Experiments
Inspired by the classic experiments in which slime molds navigate mazes to find the most efficient route to nutrients, some researchers have conducted analogous studies on fungal mycelia. Although fungi grow more slowly, the principle remains the same: place the mycelium in a maze-like environment with multiple paths to a food source, then observe how it navigates. Results often reveal that the mycelium expands out in multiple directions, then consolidates hyphal growth along the most direct or nutrient-rich path, effectively “solving” the maze over time. This optimization process supports the concept that fungi can sense and respond to spatial and chemical gradients in a manner that maximizes efficiency.
Insights from Slime Mold Research (and Why It’s Not a Fungus)
While slime molds are not technically fungi, they are often cited in discussions of brainless intelligence because of their remarkable feats—finding the shortest path in a labyrinth, approximating railway networks, and demonstrating rudimentary memory. These feats underscore the broader principle that complex problem-solving can emerge from decentralized, network-like organisms. Because slime molds and fungi share certain morphological traits—branching protoplasmic tubes in slime molds versus branching hyphae in fungi—they offer a parallel, though evolutionarily distinct, example of distributed intelligence.
Thus, slime mold research encourages mycologists to probe whether the mycelial network might exhibit similar problem-solving capacities. Although the specifics differ, both organisms challenge traditional notions of cognition by demonstrating the power of distributed information processing in achieving intelligent-like outcomes.
Philosophical and Ethical Considerations
Rethinking Consciousness and Sentience
The term “fungal mind” evokes debates about consciousness, sentience, and awareness. Philosophers and cognitive scientists have long wrestled with questions such as: “What is the minimal structure needed for consciousness?” and “Does an entity require a brain or neurons to have subjective experiences?” Although most mainstream scientists stop short of ascribing consciousness to fungi, the question pushes us to reflect on the complexity of cognition across the tree of life. If intelligence can exist without a brain, can consciousness or sentience?
Ethical Implications of Fungal Intelligence
If we grant that fungi might possess some level of intelligence or capacity to process experiences, even in a rudimentary way, it raises ethical questions. Are there moral obligations to preserve fungal habitats or to reconsider certain agricultural or industrial practices that destroy mycelial networks? Should we revise our approach to fungi in laboratory research, or in the harvesting of wild mushrooms, to minimize potential harm? This line of reasoning may seem far-fetched to some, but it fits within a broader ethical movement to acknowledge the intrinsic value of non-human life forms.
Indigenous Knowledge and Fungal Realms
Indigenous cultures worldwide have cultivated rich ethnomycological traditions, attributing spiritual significance to fungi in healing, rituals, and ecosystem management. For instance, certain tribes in Mesoamerica regard psilocybin-containing mushrooms as sacred teachers, capable of imparting wisdom and guidance. These beliefs, while not strictly “scientific,” open up cross-cultural dialogues about how humans interpret and relate to fungal life. They also highlight the importance of traditional ecological knowledge (TEK) in shaping our understanding of biodiversity and ecological stewardship.
Critiques and Counterarguments
The Reductionist Perspective: “It’s Just Chemistry”
A common critique against the “fungal intelligence” hypothesis is that all these observed behaviours—resource optimization, electrical spiking, problem-solving in mazes—could be explained by simple chemical gradients, mechanistic growth patterns, and natural selection favouring fungi that fortuitously spread in efficient ways. From this viewpoint, the mycelium’s adaptive traits are no more evidence of intelligence than the way water flows downhill is “intelligent.” Proponents of this reductionist stance argue that attributing “mind” or “thought” to fungi risks anthropomorphism and misinterpretation of basic biochemical processes.
The Need for Comparative Models
Skeptics also point out that, to validate claims of intelligence, one must conduct comparative studies across multiple species and conditions, controlling for variables like nutrient concentration, temperature, and competition. Is the “maze-solving” mycelium performing better than other physical or chemical systems under similar constraints? How does it compare with engineered systems designed for optimization, such as genetic algorithms or ant-colony optimization in computer science?
Such comparisons would help separate genuinely emergent cognitive-like processes from run-of-the-mill growth patterns. They would also clarify how unique fungal “intelligence” is when set against the backdrop of other efficient but non-cognitive processes.
Confirmation Bias in Emerging Fields
As interest in fungal intelligence grows, so does the risk of confirmation bias—the tendency of researchers and enthusiasts to interpret ambiguous data in ways that favour the intelligence hypothesis. For instance, one might observe a random pattern of electrical spiking in mushrooms and prematurely conclude it serves a communicative function, ignoring potential alternative explanations (like random ion channel openings or measurement artifacts). Rigorous peer review, replicable experiments, and cautious interpretation of data are critical to maintain scientific integrity.
Ecological and Practical Implications
Fungal Sustainability and Biomimicry
The more we learn about mycelial networks, the more potential applications emerge. Biomimicry draws on nature’s design principles to inspire human innovation. Fungal networks—efficient, resilient, and adaptive—could serve as a blueprint for distributed computing, urban planning, and logistics. Similarly, fungal materials (e.g., mycelium-based composites) are increasingly used in packaging, construction, and even clothing, tapping into the structural and regenerative properties of fungal growth.
Agriculture and Mycorrhizal Technologies
A practical angle on fungal intelligence is how mycorrhizal networks might improve sustainable agriculture. By inoculating crops with beneficial fungi, farmers can boost plant nutrient uptake, reduce fertilizer usage, and fortify plants against pathogens. Some researchers are investigating whether we can “train” or select for fungal strains that are particularly adept at resource allocation or stress management. While this is still in its early stages, it suggests a future where harnessing fungal network intelligence could be an integral part of agroecology.
Conservation of Fungal Biodiversity
Fungi often slip under the radar in conservation discussions, overshadowed by charismatic fauna like tigers or pandas. Yet, their ecological roles are indispensable. If fungal networks are indeed as complex and adaptive as the fungal mind hypothesis suggests, losing fungal biodiversity could have dire consequences for entire ecosystems. Conservation efforts therefore need to include fungi as a priority, protecting not just visible fruiting bodies but also the vast subterranean mycelial networks essential for soil health and plant communities.
Future Directions in Fungal Research
Biotechnological Applications
Fungi have already revolutionized medicine (antibiotics, statins, immunosuppressants) and food production (yeasts, fermentation). As we deepen our understanding of fungal signals and resource management, new biotechnological avenues emerge:
Fungal Sensor Arrays: Using living mycelia as sensors to detect pollutants or pathogens.
Biocomputing: Creating fungal-based computing systems that leverage the mycelium’s parallel processing capabilities.
Drug Discovery: Investigating compounds secreted in response to certain stressors could unveil new pharmaceuticals.
AI, Computation, and Fungal Systems
As scientists decode the electrical “language” of mushrooms, parallels to spiking neural networks in AI become more salient. Future research may involve training mycelial networks to perform computational tasks—routing information, solving optimization problems, or even machine learning. Although still speculative, the prospect of “mycelial AI” merges biology with computation, opening radical new horizons in both fields.
Transdisciplinary Collaborations
To unravel the full story of fungal intelligence, collaboration across disciplines is crucial. Mycologists, ecologists, neuroscientists, computer scientists, philosophers, anthropologists, and indigenous knowledge holders must come together to integrate data, theory, and cultural context. Workshops, conferences, and cross-lab projects can fuel novel questions and rigorous research methods that refine our understanding of the fungal mind.
What Does It Mean?
The emerging portrait of fungi reveals organisms of extraordinary complexity, resilience, and perhaps even a form of intelligence. Mycelial networks can sense their environment, redistribute resources in seemingly optimized ways, communicate via electrical and chemical signals, and engage in interactions with plants and other organisms that shape entire ecosystems. Whether we label this “intelligence,” “adaptive complexity,” or something else, the behaviours fungi exhibit challenge our conventional boundaries for what constitutes cognition.
Far from a fleeting curiosity, the study of fungal intelligence holds implications for fields as diverse as medicine, agriculture, technology, and philosophy. By questioning how intelligence can arise in the absence of a brain or centralized nervous system, we broaden our understanding of life’s possibilities. In turn, recognizing the sophistication of fungal systems invites deeper ecological and ethical reflection. Might we, as humans, learn from the harmonious and interdependent strategies of fungal networks? How could we cultivate a more reciprocal relationship with the living systems that sustain us?
Like the mycelium itself, the inquiry into “the fungal mind” weaves together multiple threads—scientific, cultural, and philosophical. While the definitive answer to whether mushrooms “think” may remain elusive, the journey toward comprehending fungal cognition offers a profound reminder: the natural world is more complex, subtle, and intimately connected than we have ever imagined. Through continued research, open-minded debate, and respectful curiosity, we can begin to appreciate the hidden knowledge stored in Earth’s oldest and most pervasive intelligence networks—those of the fungi.