Our pets are predators

21 01 2026

Those of us living with cats share our homes with an ancestral predator, one adapted for hunting and the frequent, exclusive consumption of meat. These instincts become fully activated outside the domestic environment, where cats pose a global threat to wildlife.

Pets are family. We celebrate their arrival with the same joy as a grand homecoming, and their absence leaves a grief as deep as losing a loved one. In bonding with cats and dogs, we often attribute human abilities and emotions to them.

But beyond this affection, domestic animals still carry the instincts and genetic legacy of their wild ancestors(1, 2). My cats — Caruso, Muesli, and Plata — have been calm and loving, but they have always enjoyed a real hunt (3). When a moth comes in through a window, they seem possessed: their mouths chitter and make clicking sounds, they leap from one piece of furniture to another, and their heads snap sharply between the insect’s position and other points in the room, calculating the best spot from which to pounce on their prey. That is why when they become feral, cats and dogs integrate into food chains like any other species: they compete for ecosystem resources, hunt and are hunted, and hybridise and exchange diseases with other carnivores (4, 5).

^{Top: cat eating an Eurasian blue tit (Cyanistes caeruleus), a common visitor to home gardens in Nijmegen (Netherlands). Bottom, domestic cat after hunting an Eastern cottontail rabbit (Sylvilagus floridanus) in a residential neighbourhood of Stratford (Connecticut, USA). Photos courtesy of Jelger Herder (Nijmegen) and Scott Kruitbosch (Stratford). Scott is a photographer and conservationist. Near sunset on 30/09/2020, while intently observing local wildlife, he witnessed a neighbourhood cat sneak up from behind on a cottontail feeding in open grass and grab it. For years, Scott has had extremely negative interactions, both in person and online, with local residents over these issues. These exchanges have revealed that many people show little concern for wildlife or for the dangers their outdoor cats face, and believe that their cats would not, or could not, harm wildlife.}

Domestic cats are highly skilled hunters, and their predatory interactions with a wide range of prey are widely documented in social media and documentaries. Some examples include cats catching: bats and birds on the wing, butterflies, chipmunks, dragons, fishes, grasshoppers, frogs, lizards, mice, owls, rabbits, seagulls, snakes, squirrels, and wallabies. See an award-winning photo depicting wildlife with fatal injuries caused by cats recorded in 2019 at a single animal hospital in the USA, and a video showing domestic cats mimicking bird calls and some cat owners explaining that their pets reject commercial cat food after experiencing the thrill of hunting real prey. The documentary Secret Life of Cats contextualises the ecological challenges posed by free-roaming cats.

Preference for native and diverse wildlife

Isac Mella and collaborators studied the prey hunted by 120 domestic cats in the Mexican city of Xalapa (6). The research was made possible through the participation of 44 residents, who were given standardised instructions to collect the animals that their cats brought home each month. From March to August 2018, the felines killed a total of 246 prey (about 41 per month), belonging to 64 different species, with 9 out of 10 being native fauna.

In terms of numbers, reptiles (36%) and invertebrates (23%) made up more than half of the captures, with the rose-bellied lizard (Sceloporus variabilis) the most hunted species (38 individuals). Hunted birds and invertebrates topped the list in terms of diversity (17 species each), followed by reptiles (15 species), and amphibians and mammals (6-9 species). The study also found that striped cats were more successful hunters likely due to their camouflage, and that captures increased the longer the animals spent outdoors (6).

^{Wildlife predation by 120 domestic cats in the areas surrounding 44 homes in Xalapa, Mexico, over 6 months (6). Histogram shows, from left to right, number of kills (red bars) and number of species killed (grey bars) for reptiles, invertebrates, amphibians, birds, and mammals. Reptiles were the most frequently hunted prey, but birds accounted for the greatest diversity of species in the cats’ menu (grey bars), including 11 species of passerines, 2 hummingbirds, 2 pigeons and doves, 1 chicken, and 1 ferruginous pygmy owl (Glaucidium brasilianum). By group, lizards (especially Anolis and Sceloporus), frogs, small rodents, grasshoppers, along with small birds such as the Wilson’s warbler (Cardellina pusilla) and the house sparrow (Passer domesticus), were the most common prey. Of the 59 species captured, 9 out of 10 were native, while 5 species (7%) were non-native. Below, dots indicate the percentage influence of various biological (green) and environmental (blue) factors on prey captures relative to the most important factor (‘time outside’). Having striped fur is the most favourable trait for hunting because it improves camouflage — more so than size, age, sex, or whether the cats are sterilised. Cats that spend more time outdoors catch more prey, while the number of daily meals at home, the size of nearby green areas or their distance from the home have little relevance. Captures decrease when cats are kept indoors at night, due to the crepuscular and nocturnal habits of many prey species such as frogs, opossums (Didelphis), six of the seven snake species, as well as the pygmy owl, bats, rabbits, shrews, and rodents. All these are minimum estimates of the prey brought home, because cats consume or abandon most of their kills at the site where they catch them (11, 30): the farther they venture, the more kills are left behind before returning home (12).}

Adapted for constant hunting

Rats and cats are the most damaging predatory mammals to global biodiversity (6). Our cat companions hunt more than 2,000 species of wildlife, including 347 that are at risk of extinction and 11 that are already extinct (7). After being introduced to over 120 islands — most of them lacking natural predators — cats have caused 14% of vertebrate extinctions and currently threaten 8% of vulnerable birds, mammals, and reptiles (8). In countries like Australia (9,37), China (10) and the United States (11), cats kill millions to billions of prey animals every year (5). The problem is both pervasive and global, as the worldwide population exceeds 600 million cats (12-14) [read here and here] and 900 million dogs (4) [read here and here] — together equivalent to the human population of China!

This predatory prowess is no accident: cats are obligate carnivores (15). Unlike the more flexible diet of dogs, a cat’s metabolism is specifically adapted to process protein-rich food (16). Their sense of taste detects the amino acids in meat, but is insensitive to sweetness (17) and shows low sensitivity to saltiness [NaCl], likely due to the high sodium [Na] content in their natural diet of meat (18, 19).

The habit of domestic cats eating several small meals a day mirrors the behaviour of their wild counterparts that hunt and consume multiple small prey throughout the day. Likewise, their tendency to lose interest in repetitive meals at home reflects an innate drive to seek prey variety, likely evolved to prevent nutritional deficiencies in their natural environment.

In short, domestic cats are evolutionarily solitary and territorial animals, compelled to hunt frequently to survive (20). This evolutionary background also explains why cats are generally more independent than dogs (21): cats grant us the privilege of living with them, while dogs — descended from the highly social wolf (22, 23) — can suffer stress or depression when left alone [watch Cats vs. Dogs: Which is Best?].

_{^{Domestic cat roaming El Haya Ecological Park in Xalapa, Mexico, where the study on the predation by these felines on wildlife was done (6). Below, another cat has just hunted a Gran Canaria giant lizard (Gallotia stehlini) in the Fataga Ravine, an endangered reptile endemic to the Canary Islands (Spain). Photos courtesy of Rafael Flores Peredo (Xalapa) and David Padilla (Gran Canaria).}}

Invasive in the wild

As a domesticated animal, the cat has no native distribution. Wherever these domestic mammals live in a feral state, they qualify as an exotic invasive species (24). Even when wearing a collar or carrying a microchip, a domestic cat roaming beyond the confines of a human home should be considered a non-native invasive animal.

In Australia, for example, domestic cats with outdoor access kill more wildlife than feral cats (9). However, in many countries such as Spain, domestic cats are not included in official invasive-species lists, creating a legal gap that hampers action. Control measures range from eradication campaigns and euthanasia, sometimes combined with sterilisation followed by release or placement into adoption programs (24, 25).

Strategies vary depending on factors like cat population density, their presence in protected natural areas or available funding. Ironically, although animal welfare advocates and conservationists often share common goals, the issue of domestic cats preying on endangered wildlife has created a deep divide between them.

Hawai’i exemplifies this conflict [watch]: feral cats contribute to the decline of endangered seabirds through direct predation (27), and threaten Hawaiian monk seals (Neomonachus schauinslandi) by spreading the protozoan parasite Toxoplasma gondii (26) that reproduces only in cat hosts (domestic, feral, and wild species). Despite this clear conservation threat, efforts to control feral cat populations face strong opposition from animal welfare groups, illustrating the tension between protecting native wildlife and concern for cat welfare.

Ideally, domestic cats should be kept indoors. If you share your life with cats, giving them full freedom to roam outdoors increases their range and the impact on wildlife, while also exposing them to greater health risks (27). For insights, watch cat management efforts in Canada and watch cat-tracking research.

If you do allow your cats outside, at the very least, restrict their outings to times when wildlife is less active (28). All measures require public support and an informed citizenry (29), because the initial reaction is often negative. People tend to see not the predator they live with, but the beloved family member they have adopted — and that emotion is projected uncritically onto all cats everywhere.

Ancestry of domestic cats. On the left, my cat Caruso with one of his fabric mice, which he often hunts at home as if it were real (Móstoles, Spain). On the right, a female African wildcat (Felis silvestris lybica) wearing a study radio collar in Kgalagadi Transfrontier Park (Botswana) — watch the species hunting birds, mice and termites. There are five subspecies of wildcat (genus Felis) in Africa and Eurasia (31) [watch wildcat diversity]. Genetics confirm that the domestic cat shares its closest common ancestor with the African wildcat [watch evolutionary story here and here] tamed in ancient Mesopotamia (2). The first tomb containing a cat, alongside the deceased’s belongings, dates to around 9,500 years ago at the Neolithic settlement of Shillourokambos, Cyprus (32). Cat domestication [watch archaeological story] might have begun with individuals that approached human settlements, where they only reproduced among themselves (33), while people tolerated them for their effectiveness in controlling pests like mice (34). The Egyptians already selectively bred different varieties, and their spread accelerated with Roman trade routes (34). Selective breeding became widespread after the Middle Ages, when coats other than the wildcat’s grey became common (1). Over time, domestic cats have evolved a range of adaptations tailored to facilitate living alongside humans (35). For example, they meow in a shorter, sharper tone than the wildcat to please and engage with people (36). Watch documentary Cat Tales exploring the human-cat history. Photos courtesy of Clara Inia Herrando (Caruso) and Marna Herbst (African wildcat).