Animals

The word animal does a lot of quiet work. It groups, under a single label, beings as different as an octopus and a cow, a hummingbird and a honeybee, a salmon and a sheep. Veganism takes that word seriously — not as an abstract category, but as a set of concrete individuals whose interests matter, one by one.

This article is the trunk of the animals pillar. It introduces who these beings are, what modern science says about their minds, the scale at which humans use them, and the relationships — not all of them industrial — we share with them.

The moral weight of scale

Before any question about cognition or welfare, there is a number problem. Human beings raise and kill more non-human animals each year than there have ever been humans in the history of the species.

According to the Food and Agriculture Organization of the United Nations, roughly 80 billion land animals are slaughtered annually for food, the overwhelming majority — chickens, pigs, cattle, ducks, turkeys, sheep, goats — raised in industrial systems (FAOSTAT). Aquatic animals push the figure into a different order of magnitude: between 1 and 3 trillion fish are caught or farmed each year, a count so large it is typically measured in tonnes rather than individuals (Mood and Brooke, 2019). Add shrimp and other decapods and the number rises by several hundred billion more.

The fact of that scale is the background against which every vegan argument is made. Whatever one concludes about the moral status of any single animal, the question repeats itself tens of billions of times a year.

What modern science says about animal minds

For most of the twentieth century, mainstream science treated claims about animal thought, emotion, and suffering with deep suspicion. That position has shifted, and the shift has been formal.

In 2012, a group of prominent neuroscientists at the Francis Crick Memorial Conference in Cambridge signed the Cambridge Declaration on Consciousness, which stated that “the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates” (Low et al., 2012).

Twelve years later, the New York Declaration on Animal Consciousness (2024) went further. Signed by dozens of researchers working on animal cognition, it stated that there is “strong scientific support” for attributions of conscious experience to mammals and birds, and “at least a realistic possibility” of conscious experience in all vertebrates — including reptiles, amphibians, and fish — and in many invertebrates including cephalopod molluscs, decapod crustaceans, and insects.

The practical upshot: the scientific default is no longer skepticism about animal minds. It is a graded confidence, species by species, that these beings experience something.

Cows

Cows are the animals most humans have met in person, often only at distance across a fence. In industrial agriculture they are used for dairy, beef, and leather; in smaller numbers, for draft work and cultural ceremony.

Behavioral research on cattle has found individually distinctive personalities, social hierarchies, strong mother–calf bonds, and the capacity to solve problems and anticipate outcomes. Calves display clear preferences in what they choose to eat and how they interact with their environment (Webb et al., 2014), and cows show measurable physiological and behavioral responses consistent with emotional states — fear, frustration, and what some researchers describe as excitement or pleasure upon solving a task (Mendl, Held, and Byrne, 2010, in related work on mammals; and a broad review tradition in applied ethology).

Female cows bred for dairy live a fraction of their natural 20-year lifespan — see The dairy industry for the reproductive architecture that defines their lives. Beef cattle in industrial systems live between a year and two before slaughter.

Pigs

Pigs are among the most cognitively studied farmed animals. The comprehensive review by Marino and Colvin (2015), Thinking Pigs, collates evidence that pigs have excellent long-term memory, are capable of simple symbolic language use in experimental settings, recognize themselves (with caveats) in mirrors, manipulate tools, show evidence of time perception, and live in complex social structures with distinctive individual personalities.

Pigs play. They respond to their own names. They experience what ethologists describe as emotional contagion — their mood shifts in response to the moods of conspecifics. They have been shown to perform better on some cognitive tasks than dogs or three-year-old children.

Worldwide, approximately 1.4 billion pigs are slaughtered each year, the vast majority in intensive confinement systems (FAOSTAT).

Chickens

The domestic chicken is the single most numerous terrestrial vertebrate on Earth. Roughly 75 billion chickens are slaughtered each year for meat, plus billions more hens kept for eggs (FAOSTAT).

Chicken cognition has been historically underrated. Marino’s (2017) review, Thinking chickens, summarizes the current state of the evidence: chickens demonstrate numerical abilities, basic arithmetic in young chicks, self-control (they can delay gratification for a larger reward), episodic-like memory, transitive inference, communication referencing specific external events, and social learning. They recognize dozens of individual conspecifics and distinguish humans by face.

The most-used land animal is also, to the best current scientific reading, a capable cognitive agent — a pairing that sits at the heart of the vegan ethical case.

Fish

Fish are the largest category of animal killed for food, and the one where scientific consensus has shifted most dramatically in recent decades.

Brown’s (2015) review in Animal Cognition argues that fish intelligence has been “dramatically underestimated” and that the cognitive capacities of many fish species are “on par with, and in some cases may exceed, those of non-human primates” on specific tasks: spatial memory, social learning, tool use, cooperative hunting, and the recognition of individual conspecifics.

On the question of pain, the work of Lynne Sneddon and colleagues has been central. Sneddon (2015) reviews the evidence that teleost fish possess nociceptors, show behavioral and physiological responses to noxious stimuli, exhibit responses that are modulated by analgesics, and make trade-offs — for example, accepting an unpleasant environment to obtain pain relief — that go beyond reflex. The conclusion is that fish very plausibly experience pain in a morally relevant sense.

Commercial fishing, aquaculture, and bycatch together make fish the largest single category of vertebrate killing humans conduct, and until recently the category drawing the least ethical attention.

Sheep and goats

Sheep and goats are kept worldwide for meat, milk, wool, and cashmere. Research on small ruminants has found sophisticated facial recognition in sheep (they can remember and distinguish dozens of individual sheep and human faces across years), social learning traditions that propagate through herds, and evidence of emotional response to separation, fear, and positive social contact.

Goats have been shown to make eye contact with humans in a way that parallels dogs’ communicative gaze — seeking a human’s help when faced with a task they cannot solve alone. That capacity for human-directed attention is not unique to animals bred as companions.

Roughly 570 million sheep and goats combined are slaughtered each year for food, with much higher populations kept for milk and fiber (FAOSTAT).

Bees and other invertebrates

The moral status of invertebrates is where the science has moved fastest. Lars Chittka’s 2022 book The Mind of a Bee brings together decades of experimental work showing that honeybees and bumblebees solve complex problems, learn by observation, display behavioral signatures of emotion-like states, use simple tools in experimental contexts, and may possess a form of awareness that earlier generations of biologists would have denied outright (Chittka, 2022).

For octopuses, squid, crabs, lobsters, and other invertebrates, the 2021 review by Birch and colleagues for the UK Department for Environment, Food and Rural Affairs evaluated more than 300 studies and concluded that cephalopod molluscs and decapod crustaceans are sentient — findings that led the UK to formally recognize these animals under its animal welfare legislation (Birch et al., 2021).

Honeybees are used for honey and, more commercially significant, for large-scale pollination of monoculture crops. The ethical position of the beekeeping industry within veganism is contested and practiced variously; the scientific claim that bees have minds worth considering is not.

Wild animals

For most of the history of animal ethics, “animals” meant farmed and companion animals. Wild animals entered the conversation chiefly through conservation — as populations and species, not as individuals.

That is beginning to change. Wild animal welfare is an emerging field that asks what we owe, if anything, to the trillions of individual wild animals whose lives are often short, often painful, and not of human making. Faria and Paez (2019) review the nascent literature, and Tomasik (2015) is among the writers who have argued that the scale of wild-animal suffering — from starvation, disease, predation, parasitism, and harsh environments — is far larger than farmed-animal suffering and deserves ethical attention in its own right.

The field is young and genuinely contested. Some vegans embrace it; others are wary of the interventionist conclusions some philosophers draw from it. What is shared is the refusal to treat the boundary between domesticated and wild as a moral cliff.

Relationships beyond agriculture

Not every human–animal relationship is a farm or a fishery. The animals pillar also covers:

• Companion animals. Dogs and cats, the most intimate animals in most human lives, raise their own ethical questions — the sourcing of pet food (much of which is meat), the welfare of purebred genetics, the ethics of breeding versus adoption, and the question of whether keeping another animal as property is itself a form of domination worth examining.
• Service and working animals. Guide dogs, therapy animals, search-and-rescue dogs, and the agricultural working animals of many cultures occupy a middle space — individuals whose work often genuinely benefits them, alongside cases that slide into exploitation.
• Wildlife coexistence. Urban wildlife, crop-raiding species, pollinators, and the animals affected by roads, lights, plastics, and climate change are in relationship with humans whether we intend it or not. Veganism asks what coexistence, rather than extermination or exclusion, would look like.
• Sanctuaries. The counter-institution to the factory farm is the farmed-animal sanctuary, where rescued individuals live out their natural lifespans. Sanctuaries are where most people first meet a cow, pig, or chicken as a person rather than a product.

Beyond individual species

Even a list this long is provisional. Two ideas cut across every species section above.

The first is sentience as a spectrum, not a cliff. The scientific consensus — from the Cambridge Declaration (Low et al., 2012) to the New York Declaration (2024) — is that consciousness is distributed widely across the animal kingdom, with graded confidence. Ethics built on that picture cannot rely on a sharp line between “beings that matter” and “beings that don’t.”

The second is systems, not just individuals. A single pig, a single chicken, a single fish is morally weighty. But the reason veganism exists as a practice rather than a feeling is that these individuals are produced, housed, and killed inside industrial systems — factory farming, the dairy industry, global fisheries — whose scale and logic no single act of kindness can reach. Species-by-species attention and system-level critique are complements, not rivals.

What this pillar covers

The animals pillar branches from this trunk into:

• Species-specific articles — cows, pigs, chickens, fish, sheep, goats, bees, and selected wild animals, each with its own cognition, welfare, and industry profile.
• Industry articles — factory farming, the dairy industry, global fisheries, aquaculture, egg production, leather, wool, down, silk, honey.
• Concept articles — sentience, speciesism, animal cognition, wild-animal welfare, personhood.
• Institutions of care — sanctuaries, rescue, rewilding, and the growing infrastructure of animal-centered law and policy.

The unifying question under all of it is simple and unreasonably large: who are these beings, and what do we owe them? Every article in this pillar is an attempt at a small, honest piece of an answer.