The Natural Composition of a Cat’s Diet – Whole Prey

What do cats eat in the wild? The answer to this question can be incredibly valuable for caretakers feeding their domestic cats a whole prey diet. It’s easy to list what constitutes a cat’s natural food: small mammals (primarily rodents), birds, and insects. However, things get more complicated when we try to determine the optimal proportions of each prey type in a cat’s diet.

Whole Prey – What Cats Would Naturally Eat

What is the best natural diet for cats? For years, the answer has widely been: whole prey. It’s also a relatively simple diet, it literally consists of feeding cats the kinds of animals they would eat in nature. These animals are served whole, with all organs, bodily fluids, feathers, and fur included.

What do we feed cats in a whole prey diet? Whatever is available from safe, disease-free, lab-tested products sold in raw pet food shops. I’m pleased to see that the offerings in such shops continue to grow. When I first began feeding my cats this way in 2015, it was difficult to find frozen mice or rats, and mastomys appeared only occasionally in their bowls as a rare treat. Over time, the menu expanded with quails sourced from retired farm layers, and one-day-old chicks were introduced — although I’d rather forget the quality of those early chicks when whole prey was still new in Poland.

These memories from a decade ago make me truly appreciate the current quality and availability of prey food for cats in 2025. Frozen mice, rats, quails of various ages, and properly handled day-old chicks have now become something of a standard. Increasingly, you can also find frozen mastomys, hamsters, gerbils, rabbits, chickens... And for cats that accept ground food, owners can expand their diets with whole-ground wild pigeons and geese.

The composition of a whole prey diet depends mainly on what we consider a cat’s natural food, and on what types of prey are available for purchase. The variety and availability of whole prey items grow each year. Yet the core question of this article remains: What would domestic cats eat in the wild — and in what proportions?

What Is the Natural Diet of Domestic Cats?

Cats were domesticated approximately 9,000 to 10,000 years ago and are now believed to descend from at least five distinct subspecies of Felis silvestris across the Middle Eastern region. It’s also believed that the domestication of wildcats coincided with the human transition from Paleolithic hunter-gatherers to a settled agricultural lifestyle in the Fertile Crescent around 12,000 years ago. Permanent human settlements meant the emergence of grain storage and garbage heaps, creating a new ecological niche for mice and rats. These rodents became a reliable food source for cats, allowing wildcats to adapt to urban environments. As humans tolerated their presence, these cats gradually diverged from their wild relatives through natural selection.

After domestication, the descendants of these wildcats were spread across the globe by humans, marking the beginnings of today’s domestic cat. Specific cat breeds are the result of intensive selection for particular aesthetic traits, although some are known as “natural breeds”, regional variants descended from the domesticated F. silvestris subspecies.

Despite their domestication, the genome structure of domestic cats remains remarkably conservative. They also retain the behavioral repertoire of their wild relatives. Modern domestic cats still closely resemble their wild ancestors in terms of genetics, morphology, and behavior. The formation of specific breeds and selection for external features in the past 50 years has likely not caused any major changes in the physiology or metabolism of pedigree cats, as they are still essentially variants of natural breeds.

What Do Wild Cats Eat in Forested Areas?

What do cats eat outdoors? Today, cats inhabit every continent and are among the most widespread species on Earth, so it’s no surprise that their diet includes an extremely broad range of prey species. In fact, it is their evolutionary adaptation to feeding exclusively on animal tissues, extracting moisture from food, and adjusting to whatever prey is locally available that has enabled cats to thrive across such a wide range of habitats.

One analysis identified as many as 2,084 species of animals consumed by cats, and that number continues to grow with each new study. It is generally accepted that around 90% of prey consumed by cats are mammals, birds, and reptiles, though the proportions vary depending on numerous factors. Occasionally, studies have also listed bats, nutrias, stoats, and even kangaroos, echidnas, and wombats as part of the feline diet.

The composition of a cat’s diet depends, among other things, on the environment it inhabits and the species available there. This makes it especially relevant to examine what forest-dwelling wild cats eat, an environment arguably closest to that of domestic cats with outdoor access. Notably, comparative studies on the diets of house cats, feral cats, and wildcats in Europe have shown that all three groups rely primarily on small mammals, albeit in varying proportions. Researchers have suggested that differences in diet composition are more likely due to variations in prey availability than differences in dietary needs.

What Do Wild Cats Eat Besides Meat?

One thing is certain: both the wild ancestors of domestic cats and their modern wild cousins are obligate carnivores. This means their diet should consist entirely of animal tissue. While studies on wild cats occasionally mention the presence of plant material, cats rely exclusively on animal tissue to meet their nutritional needs. Tiny amounts of plant matter may be consumed either in the form of partially or fully digested contents of their prey’s digestive tract, or occasionally as blades of grass.

Consuming a diet composed entirely of animal tissues throughout their evolutionary history has led to unique digestive and metabolic adaptations in cats:

1. Cats have a high dietary protein requirement because they lack the ability to significantly downregulate the activity of amino acid–catabolizing enzymes in response to low protein intake.
2. Cats are unable to synthesize arginine efficiently, making it essential that they obtain it from meat.
3. Cats are poor synthesizers of taurine, an amino acid critical for heart, eye, and nervous system function. They also rely on taurine for bile salt formation, whereas other animals can use glycine as a substitute, cats cannot. Therefore, they must constantly obtain taurine from the tissues of their prey.
4. Cats cannot convert carotenoids (like beta-carotene from carrots) into active vitamin A. They require the preformed version found only in animal products.
5. Cats cannot synthesize vitamin D from sunlight, unlike humans. They must obtain it from their diet, and it is found mainly in meat and animal fat.
6. Cats cannot effectively convert plant fats into the forms they need, they require fats from meat and organ tissues.
7. Cats are not adapted to digest sugars and starches. Their saliva contains no amylase, and their pancreas and intestines produce only limited enzymes to process carbohydrates. Their livers also struggle to metabolize glucose and fructose.

These facts make it unequivocally clear: cats are strict carnivores. Over thousands of years of evolution, their bodies have adapted to derive all necessary nutrients solely from animal tissues. Any attempt to replace their natural diet with plant-based products may lead to dangerous deficiencies. Understanding these biological limitations is essential to feeding cats correctly.

What Foods Do Cats Enjoy Most?

Studies on cat diets have been conducted around the world for over 150 years. While they haven’t always aimed to explore feline food preferences, the accumulated research allows for many conclusions. In fact, much of this research was motivated by concern about the ecological impact of cats, especially where they’ve become an invasive species threatening native wildlife.

The more widespread a given animal species is, the more frequently it appears in dietary analyses, such as house mice or sparrows. However, researchers emphasize that frequent presence in study results doesn’t necessarily reflect a strong preference by cats for those species; it could simply be due to their widespread availability across different environments. Even in human-altered ecosystems where cats primarily hunt introduced species (e.g. house mice or rabbits), they don’t ignore opportunities to hunt native prey when it’s easily accessible.

So while data confirms that small mammals and birds dominate cat diets, it’s important to remember that prey selection depends largely on the ecosystem a particular cat inhabits, that is, on what species are available in that ecological niche. Cats are not picky hunters. They eat almost anything they can catch or scavenge, including animals larger than themselves. Cats often continue hunting certain species even when their populations are declining.

Another factor is cats’ preference for prey with high energy density, prey that is more filling. Many studies have also observed strong individual hunting tendencies. Some researchers have even described cats that specialize in hunting a single prey species, even while others in the same area focus on different animals.

A cat’s diet isn’t just shaped by its environment, it also changes seasonally. These shifts result from differences in prey availability throughout the year and from the cat’s own physiological needs. For example, a nursing mother teaching her young how to hunt may favor different prey than she would during the rest of the year.

In short, cat diets are shaped by many factors. Prey availability in the local habitat is the dominant one, but seasonality, energy content, and individual preference also matter. As a result, it’s difficult to establish universal dietary rules or specific ratios. A small predator’s menu turns out to be highly flexible and diverse.

Do Cats Really Eat Rats?

Rats are among the most commonly eaten mammals by cats, especially in urban, rural, and human-transformed environments. While some cat owners may find it hard to picture their pet eating a rat, in reality, it’s a completely typical prey. One study found that rats made up as much as 95.8% of the total consumed biomass in the diet of the analyzed cats. In Australia alone, numerous rat species have been documented in feline diets, including: Rattus norvegicus, Rattus rattus, Rattus fuscipes, Rattus lutreolus, and Rattus villosissimus.

Are Rats Toxic to Cats?

This is a common myth. Rats as a species are not toxic. A cat that catches and eats a rat will not be poisoned simply by the act of eating it. The only risk comes from what the rat itself may have consumed beforehand (e.g., rodenticide) or from parasites and diseases. Wild rats can carry pathogens, which is why domestic cats should only be fed healthy, pathogen-free frozen rats sourced from reputable pet food suppliers.

Do Cats Eat the Whole Rat?

Usually, yes. Cats often consume the entire rat, including the head, bones, and internal organs. However, some cats leave behind certain parts, such as the tail or stomach. This depends on individual preference, satiety, or how fragmented the prey was. Some cats eat only the head, a part rich in fat, brain tissue, and bone marrow, which are both flavorful and calorie-dense.

Why Do Cats Like Eating Rats?

Rats are appealing prey for many reasons: they’re relatively easy to catch, move unpredictably (which strongly stimulates a cat’s hunting instinct), and provide a rich source of protein, fat, taurine, and other nutrients. Their size is large enough to satisfy hunger but small enough not to pose a threat to the cat. Additionally, cats who hunt regularly learn that rats are high-value prey and return to them instinctively.

Do Stray Cats Eat Rats?

Yes, free-roaming and stray cats regularly hunt and eat rats if they’re available. Rats are often a dietary staple for such cats, especially in cities, industrial zones, garbage dumps, or near food storage facilities.

Rats are a common part of the diet for both feral and domestic outdoor cats. Cats can eat them whole, and their digestive systems are well-suited to this type of food. While some people fear rats might be toxic to cats, the real risk lies only in rats that have ingested poison, not the rat itself. No such risk exists when cats are fed healthy, pathogen-free frozen rats from specialized prey food suppliers.

Can Cats Eat Lizards?

Although reptiles like lizards appear less frequently in dietary studies than mammals or birds, this doesn’t mean cats don’t eat them. Cats absolutely can, and do, eat lizards, and in many environments they do so regularly. However, their presence in scientific findings may be underreported due to the difficulty of identifying reptile remains in stomach or fecal samples. Additionally, reptiles tend to be much smaller than mammals or birds, meaning they account for a lower percentage of total consumed biomass.

Species of reptiles consumed by cats include geckos, agamas, skinks, monitor lizards, and even snakes, including highly venomous ones. In studies on the diets of domestic, feral, and wild cats in Europe, reptiles were more commonly consumed by cats in Mediterranean regions.

Why Do Cats Like Eating Lizards?

Lizards move quickly, erratically, and nervously, traits that strongly stimulate a cat’s hunting instincts. Their small size makes them easy to catch and treat as a snack. Nutritionally, reptiles provide high-quality protein and taurine, making them a valuable food source. Sometimes a cat may eat only part of the lizard, which may reflect individual preferences or its assessment of the prey’s nutritional value.

Can Cats Eat Frogs?

The presence of frogs in feline diets is a rarely discussed topic, mainly due to difficulties in conducting proper research. Frogs don’t have easily identifiable remains like feathers, fur, or scales, so their presence is often missed in fecal analysis. In studies from 2015 and 2019, frog DNA was detected in only 2% of cats known to have eaten frogs. Frogs are easier to detect in studies based on stomach content or wildlife camera footage.

Nonetheless, the few available studies show that frogs do appear in the diet of some cats. In Australia, for example, as many as 13% of native frog species (approximately 30 different kinds) have been recorded as part of cats’ diets. This number may be even higher, but has yet to be confirmed by data. All of these species are endemic amphibians (they don’t exist outside Australia) but some are morphologically and ecologically similar to species known in Europe, such as:

• the European green frog,
• the common frog,
• the brown frog,
• the European fire-bellied toad,
• the common toad.

Why Don’t Cats Eat Frogs?

One study found that frogs were among the most commonly killed but not eaten animals by cats. The authors suggested that this could be due to the toxicity of some frog species, which may discourage cats from eating them after a first encounter. However, this doesn’t mean that cats avoid frogs entirely. In Australia, cats were found to consume between 1 and 44 frogs per year on average, with wide individual variation. In 2017, the stomach of one cat alone was found to contain the remains of 70 frogs, and in another study, a cat monitored for 58 hours caught 35 frogs during that time.

Is It Normal for Cats to Eat Birds? Why Do Cats Eat Birds?

Bird-eating behavior in cats is completely natural and widespread, especially in habitats where birds are easily accessible. Dozens of bird species have been identified in cat diet studies and observations, including: sparrows, swifts, swallows, kingfishers, starlings, blackbirds, thrushes, goldfinches, magpies, gulls, pigeons, crows, ravens, ducks, chickens, parrots, quails, even flightless birds like emus and penguins, as well as raptors such as eagles and kites.

As always, much depends on the cats’ living environment. For example, a study in rabbit-rich parts of Sweden found that birds made up only 3% of the yearly prey mass consumed by cats. However, birds constitute a significant part of feral and wild cats’ diets on islands, where cats are invasive and where native mammal prey is scarce or absent. A strong example comes from Marion Island (South Africa), where nesting seabird colonies were studied and it was found that during specific seasons, 81.3% to 96.6% of the total prey biomass consumed by cats consisted of seabirds. In a five-year study conducted on one of New Zealand’s islands, cats were the only predators hunting adult birds and were responsible for 43% of successful predation events resulting in the death of the prey. Interestingly, the same study found that cats would kill and eat adult birds while completely ignoring nearby chicks and eggs. In contrast, another study showed cats chasing adult birds off their nests and then eating the eggs.

Cats include birds in their diets for several reasons:

• Birds are numerous, there are approximately 11,000 bird species worldwide compared to about 6,500 mammal species.
• Birds often nest on the ground or in areas accessible to cats.
• Birds are easy to spot and catch while nesting or foraging.

Another important factor is that birds are an especially nutrient-rich prey. Studies show that birds (and some insectivorous mammals like shrews and moles) contain higher levels of iron, hemoglobin, and oxygen-binding capacity than other animals. This is due to their adaptations to low-oxygen environments with high energy demands. In mammals, this relates to underground lifestyles; in birds, it’s tied to flight, one of the most oxygen-demanding activities in the animal kingdom.

In the wild, cats hunt many types of birds. In domestic settings, the safest and most practical way to include birds in a whole prey diet is to offer frozen day-old chicks or frozen quail of various ages.

Do Cats Eat Insects? Invertebrates in the Feline Diet

Although in the wild, invertebrates make up a small part of a cat’s diet, their presence is well-documented. One study analyzing 500 fecal samples from various habitats detected as many as 127 species of invertebrates. Overall, they represented no more than 0.05% of the consumed biomass, yet appeared in around 18% of the samples, indicating that insect hunting is far from rare.

The most commonly consumed invertebrate groups included:

• Orthoptera (crickets, grasshoppers, locusts),
• Butterflies and moths,
• Beetles.

The species composition varied depending on habitat, which supports the idea that cats eat what is available in their immediate environment.

In addition to insects, cats have also been found to eat:

• Snails (including shell-less stylommatophoran snails)
• Crustaceans and isopods (e.g. pill bugs)
• Centipedes and millipedes
• Hymenoptera (ants, bees, wasps)
• Cockroaches
• Earwigs
• Mantids
• Dragonflies
• Stick insects

Why Do Cats Like to Eat Insects?

Cats are opportunistic predators. They hunt whatever is available and tend to choose prey that offers the best return for the energy spent hunting. In the case of insects, this usually means they prefer larger individuals, such as grasshoppers, over small flies, although instinct often overrides satiety.

In domestic settings, it’s possible, though not necessary, to supplement a cat’s diet with insects. Reptile supply stores often offer a wide range of feeder insects, with Orthoptera (crickets, locusts, grasshoppers) being the most accessible. However, from a nutritional standpoint, the absence of insects in the diet is not a concern, as invertebrates make up only a tiny fraction of the natural feline diet.

Can a Cat Hunt a Hare?

Hares are larger and faster than most typical cat prey, but they do sometimes end up on the feline menu. In a multi-year study on cat diets in Sweden, hares made up up to 7% of the annual intake. Hunting success was slightly higher in summer than in winter, likely due to the greater availability of young hares during the warmer months.

However, rabbits are much easier prey and often make up a significant part of feline diets in various habitats. In areas with high rabbit populations, cats may even specialize in hunting them. In a long-term study on an island in New Zealand (1984–2001), rabbits were found in 77% of analyzed samples, while rodents appeared in only 17%. In the Swedish study, rabbits made up as much as 60% of the total annual prey biomass. Larger and stronger cats were more likely to hunt rabbits, perhaps because they could catch them more easily or had priority access to the best hunting grounds.

Why Do Cats Eat Rabbit Heads?

Cats often begin consuming prey with the most nutrient-dense parts, and the head contains:

• Brain tissue rich in fats and energy,
• Eyeballs, which are sources of taurine and various vitamins,
• Bone marrow from the skull, offering a concentrated source of nutrients.

Additionally, the rabbit head is relatively easy to crush and swallow compared to the heavier parts of the body, making head consumption energy-efficient.

Both rabbits and hares are natural prey for cats in the wild, which is why they are commonly included in whole prey diets for domestic cats. Pet food stores offer frozen rabbits of various sizes, from juveniles to adults, allowing portion sizes to be adjusted to the cat’s needs. Alternatively, owners can feed just the heads or opt for ground wild hare.

Do Cats Stop Eating When They’re Full?

Do cats know when they’ve had enough? In general, cats don’t eat more than they need. Many studies have shown that a significant portion of their hunted prey remains uneaten. One such study found that 28% of captured prey was not consumed at all, while others report that nearly 49% of kills are abandoned after a successful hunt. This is especially true for outdoor domestic cats, who often eat less than one-third of what they catch. The average hunting success rate in such cases is around 44%, meaning nearly every second hunt ends in a catch, but not necessarily in consumption.

This behavior is not due to a lack of hunger, but rather a natural response to the availability of easy prey. As opportunistic hunters, cats will rarely pass up the chance to catch vulnerable prey, even when they’re not hungry. For example, in post-fire areas or heavily grazed landscapes, where prey has difficulty escaping, cats catch much more than they eat. Interestingly, neutering does not significantly affect a cat’s hunting abilities. Both spayed/neutered and intact cats display similar tendencies and success rates in hunting.

Many studies confirm that cats, whether domestic, feral, or wild, do not rely on a single universal type of food. Their diet depends on various factors: prey abundance and availability, ease of capture, energy content, nutrient density, and even moisture content, especially during periods when water is scarce.

While a whole prey meal provides a complete nutritional profile that satisfies all of a cat’s dietary needs, science doesn’t offer a single definitive formula for how to build such a diet. In the wild, some cats specialize in hunting specific types of prey (e.g. birds or rabbits), while others have extremely varied diets. A sensible approach is to maximize variety, considering both the cat’s instinctive preferences and its natural ability to assess the nutritional value of prey.

References

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Article text: inessiwinska@gmail.com