Honey bees are the strongest single candidate for the title of most intelligent insect, with demonstrated abilities in abstract numerical reasoning, symbolic communication, and what some researchers describe as a basic form of metacognition. But the honest answer is that “most intelligent” depends on which dimension of intelligence you care about. Paper wasps recognize individual faces using the same kind of holistic processing humans rely on. Ants select, modify, and deploy tools with surprising flexibility. Dragonflies run predictive models of prey motion mid-flight. The insect world does not have one genius species and a bunch of dullards; it has dozens of lineages that have each pushed cognitive specialization in different directions.
The Case for Honey Bees
If you had to pick one species, honey bees keep showing up at the top of the list because they perform well across the widest range of cognitive tests. In 2018, researchers demonstrated that honey bees understand the concept of zero, placing it correctly on a numerical continuum as “less than one.” That puts them in a small club of animals known to grasp the empty set, alongside primates and some birds.1Science. Numerical ordering of zero in honey bees The finding was striking enough that the journal’s editors noted it suggests an understanding of “nothing” has evolved independently across distantly related species.2Science. Honey bees zero in on the empty set
Bees also show something resembling awareness of their own uncertainty. When trained on a visual discrimination task where correct choices earned sugar water and wrong choices delivered bitter quinine, honey bees given the option to simply leave the trial preferentially opted out of the hardest ones, boosting their overall success rate. Whether this counts as true metacognition or is better explained by associative learning is debated, but either way it reflects a sophistication in decision-making that most people would not expect from a brain smaller than a sesame seed.3Proceedings of the National Academy of Sciences. Honey bees selectively avoid difficult choices
Then there is the waggle dance, one of the most elaborate communication systems in the animal kingdom outside of human language. A foraging bee returning to the hive performs a figure-eight dance whose angle relative to gravity encodes the direction of a food source relative to the sun, while the duration of the waggle phase encodes distance. Automated tracking systems can decode the dance direction with an average error of just a few degrees, confirming how precisely the information is transmitted.4PubMed Central. Automatic detection and decoding of honey bee waggle dances This is not a simple alarm call or pheromone trail. It is symbolic, referential communication about locations the audience has never visited.
Paper Wasps and the Power of Recognition
Paper wasps of the genus Polistes may not have the public profile of honey bees, but they display cognitive abilities that are, in some ways, more surprising. Polistes fuscatus wasps recognize other individual wasps by their facial markings, and they do so using holistic face processing, the same perceptual strategy that humans use. Rather than analyzing individual features one at a time, they perceive the face as a unified pattern. Experiments using a modified version of the classic “part-whole test” from human psychology showed that P. fuscatus rely on this holistic approach for conspecific faces but not for the faces of a related species they do not need to tell apart individually.5PubMed Central. Individual recognition is associated with holistic face processing in Polistes paper wasps in a species-specific way Their close relative P. dominula, which does not use individual recognition socially, treats faces as generic patterns. The specialization in P. fuscatus is innate and does not require experience with faces during development to emerge, though in a related species, P. metricus, experience can help bootstrap a similar ability.6Animal Behaviour. The development and evolution of specialized face learning in paper wasps
Paper wasps also pass tests of transitive inference, a form of logical reasoning. If you train a wasp that stimulus A beats stimulus B, and B beats C, and so on down a hierarchy, the wasp can then correctly infer that B should beat D in a novel pairing it was never directly trained on. Both P. dominula and P. metricus chose the higher-ranked stimulus significantly more often than chance on these novel pairings, performing about as well on inferential trials as on the trained ones they had already practiced.7PubMed Central. Transitive inference in Polistes paper wasps This kind of reasoning was once thought to require a mammalian-sized brain.
Social Learning and Play in Bumble Bees
Bumble bees do not have the waggle dance or the zero concept, but they have become a focal species for studying social learning in insects. In a well-known experiment, researchers trained individual bumble bees to pull a string to access a hidden flower reward. Untrained bees that watched a skilled demonstrator were far more likely to solve the task on their first attempt: about 60% of observers succeeded immediately after watching, compared with nearly zero success in bees that had never seen it done.8PLOS Biology. Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect Further work showed this skill can spread across colonies under naturalistic “open diffusion” conditions, where bees interact freely rather than being tested one at a time. In experimental colonies seeded with a single trained demonstrator, 25 bees across three colonies learned the technique, compared to just two bees across three control colonies that had no demonstrator.9Animal Behaviour. Bumble bee string-pulling skill spreads between colonies under open diffusion conditions
Bumble bees have also demonstrated foraging behaviors that spread socially. Experience with robbed flowers, where a hole bitten in the base lets a bee “steal” nectar without pollinating, promotes the development of primary robbing in bees that had previously foraged legitimately. The behavior feeds back on itself: one robber creates holes that recruit more robbers, and the technique spreads at accelerated rates consistent with social transmission.10PubMed Central. Social transmission of nectar-robbing behaviour in bumble-bees
Perhaps the most unexpected finding in bumble bee cognition involves play. Researchers presented Bombus terrestris with small wooden balls in an arena and found that bees repeatedly rolled them in ways that met established behavioral criteria for animal play: the activity had no immediate survival benefit, appeared intrinsically rewarding, differed in form from functional behaviors like foraging, was repeated without being stereotyped, and occurred only under stress-free conditions.11Animal Behaviour. Do bumble bees play? Whether the bees experience something like fun is an open question. But the behavior pattern mirrors play in vertebrates closely enough to raise real questions about insect sentience.
Tool Use in Ants
Tool use is a classic yardstick for animal intelligence, and several ant species pass it convincingly. Ants of the genus Aphaenogaster encounter liquid food sources they cannot drink directly or carry, so they drop debris into the liquid, wait for it to soak up, and carry the soaked tool back to the nest. This alone is interesting. What makes it more impressive is that the ants are selective about their tools. Aphaenogaster subterranea workers preferred small soil grains over leaf fragments even though leaves had superior soaking power, apparently because smaller items were easier to transport.12Animal Behaviour. Tool selection during foraging in two species of funnel ants When researchers varied the distance between tools and food and the types of tools available, the ants adjusted their choices in real time, selecting less-preferred larger tools when those were discovered first or positioned more accessibly. They also refined their tool use at two distinct stages: when dropping tools into the liquid, and again when retrieving the soaked tools to carry home.13Behavioral Ecology. Which tools to use? Choice optimization in the tool-using ant, Aphaenogaster subterranea
Black imported fire ants go a step further. When foraging on sugar water where the surface tension was reduced by adding surfactant, increasing the risk of drowning, fire ants switched from floating on the surface and drinking directly to building structures out of sand grains that effectively functioned as siphons, drawing the liquid out of the container without the ants ever entering it.14Functional Ecology. Ants adjust their tool use strategy in response to foraging risk This is not a fixed behavior triggered by a chemical cue. The ants assessed the risk and selected an entirely different strategy in response.
Specialist Hunters With Specialized Brains
Not all insect intelligence looks like problem-solving or communication. Dragonflies are aerial predators that catch prey mid-flight with a success rate far higher than most vertebrate hunters. Research tracking the position and orientation of a dragonfly’s head and body during pursuit flights revealed that these insects use internal models to predict where prey will be, continuously adjusting their body alignment to intercept the target’s flight path. Vision is reserved mainly for reacting to unexpected prey movements; the bulk of the steering is model-driven, meaning the dragonfly is essentially running a physics simulation of its target’s trajectory in real time.15Nature. Internal models direct dragonfly interception steering This kind of predictive control was long assumed to require the neural infrastructure of a vertebrate brain.
Praying mantises, meanwhile, have evolved a form of stereoscopic vision that works on completely different principles from vertebrate stereo vision. Rather than comparing static luminance patterns between the two eyes, mantis stereopsis detects regions where luminance is changing. This means it works poorly with static images but excels at gauging distance to moving targets, even when those targets are perfectly camouflaged against the background in terms of texture. In certain test conditions, mantises actually outperformed human observers at judging stereoscopic distance when the luminance patterns in the two eyes did not match.16PubMed. A Novel Form of Stereo Vision in the Praying Mantis Researchers confirmed this using tiny 3D glasses fitted to mantises in a custom “insect cinema,” demonstrating that the animals responded to simulated disparity cues just as they would to real depth.17Scientific Reports. Insect stereopsis demonstrated using a 3D insect cinema
Navigation Without a Map
Desert ants of the genus Cataglyphis are famous for navigating vast, featureless landscapes to find their way home after foraging trips that may cover hundreds of body lengths. The core mechanism is path integration: the ant continuously tracks its own movements and computes a “home vector” pointing back to the nest. But these ants do more than retrace their steps. When trained to visit two separate feeders, they can compute and travel a shortcut between the two locations that they have never actually walked before. This appears to arise from the interaction between memorized goal vectors stored in long-term memory and the continuously updated path integrator.18PubMed Central. Vector-based navigation in desert ants: the significance of path-integration vectors
Visual navigation adds another layer. Ants that travel along familiar routes appear to use a strategy called “cast and surge,” where they sample the visual familiarity of their surroundings by turning in place, identify the heading that matches their stored visual memories, then surge forward along that heading. Modeling work has shown this strategy is significantly more robust at keeping an ant on its route compared to simpler visual-compass approaches, even when the ant is displaced from its usual path.19PLOS Computational Biology. Ant visual route navigation: How the fine details of behaviour promote successful route performance and convergence These are not GPS-equipped mammals. They are running complex navigational algorithms on a brain with roughly a quarter of a million neurons.
Individual Brains Versus the Superorganism
One reason the “most intelligent insect” question resists a clean answer is that many of the most impressive feats of insect cognition are collective. A single honey bee can learn a color association. A colony of honey bees can collectively select the best nest site from among several candidates through a democratic process that resembles Bayesian decision-making. The relationship between individual cognition and colony-level cognition spans a wide spectrum, from simple amplification of individual abilities to genuinely emergent group-level processes that no single insect could achieve alone.20PubMed Central. Individual versus collective cognition in social insects
This creates an awkward measurement problem. If you are asking which individual insect is smartest, you are testing it alone in a lab. But many social insects evolved their individual cognitive abilities precisely because they operate inside a colony. Their brains are tuned for social context. Isolating them may underestimate their real-world intelligence in the same way that testing a human’s cognitive abilities while forbidding them to use language, writing, or tools would underestimate ours.
Brain Size, Caste, and Flexibility
Insect brains range from roughly 10,000 neurons in some tiny parasitoid wasps to about a million in larger species like cockroaches and dragonflies. Brain size in insects correlates with body size as a general rule, but relative brain size varies with factors like social complexity and the demands of learning and memory.21Europe PMC. A Review of Effects of Environment on Brain Size in Insects What stands out about insect cognition, though, is how much these small brains accomplish. The computational efficiency is extraordinary when you consider that a honey bee performs abstract numerical comparisons with about 960,000 neurons, while a human brain uses 86 billion for the same task.
In some species, brain size is not even fixed within an individual’s lifetime. In the ant Harpegnathos saltator, workers that transition into reproductive “gamergates” undergo a roughly 19% reduction in brain volume, along with changes in behavior, gene expression, and physiology. Remarkably, this transition is reversible: if social conditions change, gamergates can revert to a worker-like state and regain brain tissue.22Proceedings of the Royal Society B: Biological Sciences. Reversible plasticity in brain size, behaviour and physiology characterizes caste transitions in a socially flexible ant (Harpegnathos saltator) The ant effectively remodels its own brain depending on its current social role, trading cognitive capacity for reproductive investment and back again.
When Cognition Gets Disrupted
The sophistication of insect cognition also means it is vulnerable. Neonicotinoid pesticides, the most widely used class of insecticides worldwide, act on the same nicotinic acetylcholine receptors that are central to learning and memory formation in insect brains. Bumble bees exposed to field-realistic concentrations of the neonicotinoid thiamethoxam learned a color-reward association about 27% more slowly than unexposed controls, and their short-term memory was significantly impaired at concentrations as low as 2.4 parts per billion.23PubMed Central. Bumblebee learning and memory is impaired by chronic exposure to a neonicotinoid pesticide In honey bees, acute exposure to another neonicotinoid, clothianidin, disrupted both the consolidation and retrieval of memory, meaning it interfered not just with forming new memories but with accessing ones already stored.24PubMed. The neonicotinoid clothianidin impairs memory processing in honey bees
These are not lethal doses. The concentrations used in these experiments reflect what bees actually encounter in agricultural landscapes. A bee that cannot learn which flowers are rewarding, or that forgets the route home, is functionally compromised even if it survives the exposure. The practical implication is that the cognitive abilities researchers have spent decades documenting in bees are exactly the abilities that widespread pesticide use is degrading. Whether the most intelligent insect can stay that way under current agricultural conditions is a question the science is still working out.