A growing body of research suggests that many animals do experience something that functions like boredom, even if we cannot ask them to describe it. Scientists who study animal welfare have proposed that boredom involves two measurable components: low arousal, meaning the animal is understimulated, and an aversion to that monotony. That framework, first laid out in detail in a 2017 paper in Animal Behaviour, has opened the door to studying boredom objectively rather than dismissing it as an unknowable inner state. The findings so far paint a picture that is both more nuanced and more concerning than most people expect.
What Boredom Means When You Cannot Ask
The biggest obstacle to studying boredom in animals has always been the obvious one: you cannot interview a dog or a parrot about how they feel. For years, that difficulty led many researchers to avoid the topic entirely. Attributing boredom to animals felt too close to anthropomorphism, the cardinal sin of animal behavior science. But the field has shifted. Researchers now argue that boredom can be broken down into components that are measurable without relying on self-report.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation
The key insight is that boredom has two qualities you can observe from the outside. The first is arousal, essentially how alert and engaged the animal is. A bored animal has suboptimal arousal: it is understimulated. The second is valence, how pleasant or unpleasant the experience is. Boredom is unpleasant. It is not simply relaxation or contentment with quiet surroundings. It is an aversive state that the animal is motivated to escape. When researchers frame boredom in those terms, it becomes something you can test for without ever needing the animal to fill out a questionnaire.
The Paradox of Sleepy and Restless at the Same Time
One of the stranger predictions in boredom research, and one that the evidence increasingly supports, is that bored animals show what looks like contradictory behavior. Because their arousal is dropping, they drift toward drowsiness. But because that low arousal feels bad, they periodically snap out of it with bursts of restlessness, sensation-seeking, or attempts to interact with whatever is available. A bored animal might spend stretches lying still with eyes half-closed, then suddenly pace, chew on something inappropriate, or start antagonizing a cage-mate, only to sink back into apparent lethargy. This alternating pattern is different from both simple tiredness and simple frustration.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation
Researchers have looked for exactly this pattern in laboratory ferrets and found it. Ferrets kept in standard cages showed signs consistent with boredom, including restless sensation-seeking combined with indicators of suboptimal arousal. When the researchers gave the ferrets extra daily play sessions, the hypothesis was that those sessions would reduce restlessness, aggression, sensation-seeking, and that drowsy-but-awake state, even a full day later back in the home cage.2PubMed Central. Does ‘playtime’ reduce stimulus-seeking and other boredom-like behaviour in laboratory ferrets? The study was designed around the idea that if boredom is a real state with predictable behavioral outputs, then relieving monotony should reduce those outputs in a coherent way, not just change one behavior randomly.
This is a useful test of the concept. If what looked like boredom was actually something else, like general anxiety or illness, a play session would not be expected to fix all those different symptoms at once. But the pattern researchers observe in understimulated animals fits the boredom model better than the alternatives.
What Chronic Understimulation Does to Animals
When boredom is not a passing afternoon but a permanent condition, the consequences go far beyond looking listless. Research on mink in monotonous, stimulus-poor environments has shown that chronic understimulation can produce an increased motivation for any kind of diverse stimulation, consistent with what we would call boredom. But left unaddressed, that state can deepen into something worse: depression-like behavior and even self-injury.3Animal Welfare. Is boredom an animal welfare concern? The trajectory seems to go from boredom to desperation to something resembling giving up, a progression that has troubling parallels to what happens in humans deprived of stimulation.
In laboratory mice, barren cages produce a well-documented escalation. Normal exploratory behavior, like climbing, can transform into stereotypies: repetitive, seemingly purposeless actions such as gnawing on cage bars or spinning from the cage lid. These behaviors appear when mice try and fail to cope with an environment that gives them nothing meaningful to do.4Applied Animal Behaviour Science. Do Laboratory Mice Get What They Need From Their Cages? Stereotypies are one of the clearest red flags in animal welfare science because they signal that the animal’s coping mechanisms have broken down. A mouse spinning on the cage lid is not playing. It is stuck in a behavioral loop that has replaced the exploration, foraging, and problem-solving its brain was built for.
A systematic review of environmental enrichment studies in laboratory rats and mice reinforced this picture, finding that confinement and understimulation carry potentially harmful effects on both mental and physical health.5PubMed Central. Bored at home?-A systematic review on the effect of environmental enrichment on the welfare of laboratory rats and mice Understimulated rodents do not just behave differently. Their brains change. Chronic boredom appears to harm neural, cognitive, and behavioral flexibility, meaning the animal literally becomes less capable of adapting to new situations the longer it stays in a monotonous one.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation This is not just an animal feeling bad in the moment. It is lasting damage to how the brain works.
The Gap Between Wild and Captive Days
One way to understand why captive animals might be vulnerable to boredom is to compare how they spend their time with how their wild counterparts do. These comparisons consistently reveal that captivity compresses and flattens an animal’s daily schedule. Wild chimpanzees at Mahale Mountains National Park in Tanzania, for instance, spend a significantly larger proportion of their day foraging than captive chimpanzees at a Japanese zoo.6PubMed Central. Comparisons of Activity Budgets, Interactions, and Social Structures in Captive and Wild Chimpanzees (Pan troglodytes) In the wild, finding and processing food is a cognitively demanding, time-consuming activity. In captivity, food arrives on a schedule in a bowl. The hours that would have been filled with problem-solving, traveling, and social coordination around food are suddenly empty.
A 2025 systematic review comparing wild and zoo-housed animals across multiple species groups found consistent differences. Zoo-housed primates showed the largest gap in foraging behavior relative to their wild counterparts, while other groups showed different patterns. Parrots in captivity differed most in how much time they spent out of sight and in aggressive interactions. Carnivores showed their biggest captive-wild gap in reproductive behavior.7Frontiers in Ethology. What behavior is important behavior? A systematic review of how wild and zoo-housed animals differ in their time-activity budgets The details vary by species, but the theme is the same: captivity removes the activities that would normally occupy an animal’s day, and the remaining time gets filled with resting, pacing, or doing nothing at all.
A study of Sulawesi crested black macaques found more rest and less movement and feeding in captivity than in the wild, though the differences did not reach statistical significance in that particular study.8Animal Welfare. A Comparison of the Activity Budgets of Wild and Captive Sulawesi Crested Black Macaques (Macaca Nigra) Even when the overall activity budgets did not differ dramatically, the quality of the activities changes. Resting after a day of foraging through a forest is different from resting because there is nothing else to do. The numbers alone do not always capture that distinction, which is part of why boredom has been so hard to study.
Can You Test Whether an Animal Sees the World Pessimistically?
Beyond watching behavior, researchers have developed cleverer ways to ask whether understimulated animals are experiencing something emotionally negative. One approach uses something called cognitive bias testing. The idea is simple in concept: train an animal to associate one cue with a reward and a different cue with something neutral or unpleasant, then present an ambiguous cue that falls between the two. An animal in a negative emotional state tends to interpret that ambiguous cue pessimistically, as if it expects the bad outcome. An animal in a positive state leans optimistic.
The landmark study in this area showed that rats housed in unpredictable, stressful conditions, which produce depression-like symptoms, were more inclined to respond negatively to ambiguous cues than rats in stable, familiar housing.9PubMed Central. Cognitive bias in animal behavior science: a philosophical perspective This does not prove those rats were bored specifically. But it demonstrates that animals in unfavorable conditions experience something that shifts their emotional outlook in measurable ways. It is one more piece of evidence that the internal states of animals are real, have consequences, and can be detected without requiring the animal to talk about its feelings.
This kind of research matters because the skeptic’s strongest argument against animal boredom has always been: how do you know they are not just inactive? Cognitive bias testing provides a partial answer. An animal that is merely resting would not be expected to interpret neutral cues negatively. An animal that is experiencing something unpleasant, whether we call it boredom, frustration, or malaise, would.
Enrichment That Actually Changes the Picture
If boredom is a real welfare problem, the obvious follow-up is whether you can fix it. The enrichment literature offers encouraging results, though the specifics matter more than the general principle of “give them something to do.”
Puzzle feeders have emerged as one of the most reliable tools. A study of captive golden-headed lion tamarins found that food puzzles increased the time the animals spent actively engaged with food from about 15 minutes with standard bowls to about 47 minutes with puzzles, roughly a threefold increase.10PubMed Central. Short-Term Puzzle Feeder Enrichment Increases Food Engagement but Not Stress-Related Behaviour in Captive Golden-Headed Lion Tamarins That matters because it reclaims some of the foraging time that captivity strips away. The tamarins were not just eating more; they were spending more of their day doing something cognitively engaging. The study did note that short-term puzzle exposure did not significantly reduce stress-related behaviors like excessive grooming, suggesting that enrichment may need to be sustained and varied to address the full picture.
Large captive cats at a Brazilian zoo responded to a “surprise box” enrichment method involving pieces of meat hidden inside cardboard boxes. The intervention increased social and rest behavior while reducing idle downtime.11Journal of Veterinary Health Science. Environmental Food and Cognitive Enrichment: A Study of Well-Being for Large Captive Felids at the Zoo of Goiânia The fact that rest went up alongside social behavior, rather than replacing it, suggests the cats were experiencing a more natural rhythm of activity and recovery rather than the flat inactivity of chronic understimulation.
The enrichment concept has even been extended to fish. A study on captive guppies explored whether fish would choose a puzzle feeder over freely available food, which is a standard test for whether an animal values cognitive challenge for its own sake. The researchers concluded that cognitive enrichment holds potential significance for captive fish welfare.12Ethology. Do captive fish need cognitive enrichment? A test with a puzzle feeder in guppies If even guppies appear to benefit from problems to solve, the range of animals capable of something like boredom may be far wider than people assume.
Why Boredom Likely Has an Evolutionary Purpose
It is tempting to think of boredom as a malfunction, a defect of being stuck in the wrong environment. But researchers have argued it is better understood as an adaptive signal. Boredom motivates exploration and learning. An animal that felt perfectly content sitting in the same spot, eating the same food, interacting with nothing new, would miss opportunities and fail to develop the cognitive flexibility needed to survive in a changing environment. The unpleasant feeling of boredom pushes the animal to seek out novelty, which in the wild would lead to discovering new food sources, learning new skills, or building more complex social relationships.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation
This framing helps explain why captivity is so problematic. The signal is firing, telling the animal to go find something new, but the environment offers nothing new to find. It is like being hungry with no food available. The drive does not shut off just because satisfying it is impossible. Instead, the animal is stuck in a loop of wanting stimulation and failing to get it, which over time produces the behavioral deterioration researchers observe.
The argument also implies that the neurological hardware for boredom may be widely shared across species. If boredom evolved because it promotes adaptive behavior, any animal that benefits from exploration and learning, which includes a vast range of species, might have the capacity for it. The basic brain systems involved in arousal and reward are broadly conserved across vertebrates, which is consistent with the evidence that mammals, birds, and even fish show signs of needing cognitive stimulation.
How Time Perception Fits In
One of the most recognizable features of human boredom is the feeling that time is dragging. Minutes feel like hours. Researchers have suggested this is not just a quirk of the experience but a defining feature. If that is right, then fully understanding whether an animal is bored might require knowing whether it too perceives time as passing slowly under monotonous conditions.
This sounds impossibly subjective, but it can actually be tested. Animals can be trained on timing tasks, where they learn to respond after a certain interval, and researchers can then measure whether their time estimates shift depending on their housing conditions or emotional state. The authors of the 2017 framework paper explicitly proposed that the effect of monotony on time perception could be behaviorally assayed in animals, making it a testable component of boredom rather than an untouchable philosophical mystery.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation
This is still frontier territory. The research on time perception in bored animals is sparse compared to the work on behavioral signatures and enrichment. But the fact that it is testable at all is significant. It means the question of whether a rat or a parrot experiences the subjective crawl of time during monotony is not permanently locked behind the problem of animal minds. It is an empirical question waiting for more data.
What Boredom Research Means for Animals in Your Home
Most of the formal research on animal boredom comes from laboratory and zoo settings, where conditions can be controlled and measured. But the implications extend directly to pets. A dog left alone in an apartment for ten hours with no toys, no social interaction, and no opportunity to explore is living in something structurally similar to a barren cage. The same goes for a single parrot in a small cage, a hamster in an undecorated enclosure, or an indoor cat with no outlets for hunting behavior.
The research suggests that the most effective enrichment is not just physical activity, though that helps, but cognitive engagement. Puzzle feeders, training sessions, novel objects, foraging opportunities, and social interaction all address different aspects of the understimulation problem. Variety matters too. A single enrichment item that never changes becomes part of the monotony rather than a cure for it. The mink research and the golden-headed lion tamarin work both point toward the same principle: animals need not just stimulation but a degree of unpredictability and challenge to stay psychologically healthy.3Animal Welfare. Is boredom an animal welfare concern?
One practical suggestion from the welfare literature is to give animals some choice in the level of stimulation they experience. Rather than deciding for the animal what it needs, offer options. A cat with access to both a quiet hiding spot and an interactive toy can regulate its own arousal. A dog with access to a window, a puzzle, and a comfortable resting area has more ability to match its environment to its internal state. The goal is not constant excitement but the opportunity to seek stimulation when the animal wants it, which is exactly what boredom as an adaptive signal is designed to promote.
A Field That Barely Exists Yet
For all the evidence that has accumulated, one of the most striking observations from researchers in this area is how young the field is. Biological research into animal boredom has barely begun, despite having important implications not only for animal welfare but for understanding the evolution of motivation and cognition more broadly.1Animal Behaviour. Bestial boredom: a biological perspective on animal boredom and suggestions for its scientific investigation The tools exist. The behavioral predictions are testable. The welfare stakes are clear. What has been missing is the scientific community’s willingness to treat boredom as a legitimate object of study rather than an anthropomorphic projection.
That reluctance is gradually fading. The fact that boredom can now be decomposed into measurable components, arousal levels, behavioral indicators, cognitive biases, time-perception shifts, has made it respectable in a way it was not two decades ago. Welfare science has also pushed the conversation forward by documenting the real harm that understimulation causes, making it harder to argue that boredom is just a human metaphor being carelessly applied to animals. The question is no longer really whether animals can get bored. It is how many species are affected, how severe the consequences are, and what we are obligated to do about it in the billions of animals we keep in farms, labs, zoos, and homes.