Cats can smell the difference between their human friends and strangers from just a few sniffs of our body odor, a new study suggests.

Domestic cats (Felis catus) use smell to communicate with each other and hunt, so it's an important sense for our feline friends. However, the new study, published May 28 in the journal PLOS One, marks the first time researchers have tested whether cats can distinguish different humans by smell.

The researchers found that cats spent longer sniffing a scent swabbed from a stranger than the scent of their owner, which indicates our pets recognize humans they are familiar with and put more energy into learning strange smells from people they don't know.

"A shorter sniffing time suggests that when cats came across the smell of their guardian, they recognised it quickly and moved along," Julia Henning, a doctoral candidate researching feline behavior at the University of Adelaide in Australia, who was not involved in the study, wrote in The Conversation. "But when they came to the swabs from an unknown person, the cat sniffed longer, using their superior sense of smell to gather information about the scent."

Related: Scientists solve mystery of how orange cats got their coats — and why so many are male

Previous studies have established that cats recognize their owner's voices and distinguish between familiar and unfamiliar human faces — though they're not as good at this as dogs. Cats can also pick up on changes to their owner's emotional states, some of which they recognize through body odor. However, until this latest research, researchers didn't know the extent to which cats can recognize different humans from scent alone.

In the new study, researchers presented cats with three plastic tubes; one containing the scent of their owner, one containing the scent of a stranger and one containing no human scent to act as a control. The scientists obtained the scents by swabbing human participants under the armpit, behind the ear and between the toes.

The findings that cats spend longer sniffing a stranger's scent than their owner's (or the control) align with previous research about cat smelling behavior. For example, weaned kittens smell unknown female cats for longer than their mothers, so there's a relationship between smell length and familiarity.

In addition to smelling for longer, the researchers also found that cats were more likely to sniff the unknown odors with their right nostril first, before switching to their left nostril. This nostril preference suggests that cats use different sides of their brain for different tasks, which scientists have found to be the case in dogs, fish and some other animals too, according to the study.

While the new findings suggest that cats can at least distinguish between familiar and unfamiliar people, researchers still don't know whether cats can tell the difference between specific people with whom they are familiar.

"The odor stimuli used in this study were only those of known and unknown persons," study co-author Hidehiko Uchiyama, a professor at the Tokyo University of Agriculture in Japan, told BBC News. "Behavioral experiments in which cats are presented with multiple known-person odor stimuli would be needed, and we would need to find specific behavioral patterns in cats that appear only in response to the owner's odor."

Paws what you're doing, it's time for the ultimate cat quiz.

Cats are adorable. Fact! From their squishy "toe beans" to their swishy tails, they've made their way into our homes and our hearts. They're one of the world's most popular pets, but how much do we really know about our fluffy friends?

Our cuddly (and sometimes not so cuddly) companions have been intertwined with human lives for millennia: the ancient Egyptians were obsessed with cats, you've probably heard of the famous Schrödinger's cat thought experiment, and if you've been on the internet long enough, you'll have come across cat celebrities like the lovable Grumpy Cat and Lil BUB.

Yet, despite thousands of years together, there are many cat questions left unanswered. Why do they purr? What do their miaows and chattering actually mean? And who really domesticated who?

Take the quiz below to find out if you're the cat's whiskers or just kitten yourself. Only the cleverest of kitties will land on their feet in this quiz. Pspspsps… check out our big cats quiz too!

If you need a hint, click the yellow button. Good luck!

More science quizzes

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The earliest known domestic cat in what is now the United States perished 466 years ago in a shipwreck off the coast of Florida, a new study finds.

The ship was part of a Spanish colonizing expedition led by the conquistador Tristán de Luna y Arellano, who was voyaging from Mexico under the Spanish crown. In September 1559, a hurricane in Pensacola Bay wrecked several of the 11 ships, which had been anchored near the new Spanish settlement of Santa María de Ochuse. Researchers found one of these wrecks, known as Emanuel Point II, in 2006. This shipwreck holds the remains of an adult and a juvenile domestic cat (Felis catus), according to the new study, which was published April 14 in the journal American Antiquity.

"Our current understanding is that all domestic cats come from ancestors in the Middle East. So, they had to be introduced to the Americas by people," said study co-author Martin Welker, an anthropological archaeologist who specializes in zooarchaeology at the University of Arizona.

Archaeologists had previously found domestic cat remains in other early Spanish settlements, including the Indigenous Taíno town of En Bas Saline in what is now Haiti, where Chistopher Columbus landed in 1492. But Columbus never made it to continental North America. Instead, "the Spanish expeditions in Florida were really the first opportunities for domestic cats to reach what is today the U.S.," Welker told Live Science in an email.

Related: Pet cats arrived in China via the Silk Road 1,400 years ago, ancient DNA study finds

The team analyzed the cat bones using several techniques, including zooarchaeological (comparing the bones from the shipwreck to the bones of modern cats), isotopic (surveying different chemical signatures) and genetic (studying ancient DNA) analyses, Welker said. The results confirmed that the bones belonged to domestic cats and provided insights into their feline ancestries as well as the adult cat's diet.

"What was interesting, is that our cat was not eating the rats on board the ship but had a diet more in line with what we'd expect for the sailors," study co-author John Bratten, an anthropologist at the University of West Florida, told Live Science in an email. This indicates that the sailors fed the adult cat either because the rats did not provide enough food, or out of affection, the researchers wrote in the study.

"It was interesting to think about the idea of the cat being a pet or one that was looked after by the Spanish sailors," Bratten added.

The genetic analyses suggest that both the adult and juvenile cats descended from European relatives. While it's impossible to determine how the cats got onto the ship, one idea is that they slipped aboard while it was anchored or docked in Mexico before sailing for Florida, Bratten said.

However, they may have been brought aboard intentionally, given that cats helped control the rat and mice populations that could get into food supplies and transmit diseases, Welker said.

It wouldn't be surprising if the cats had been mousers, because "from their domestication until their arrival in the New World, cats' primary role in many communities was pest control, something that they were well suited to and that required little supervision from their human cohabitants," the researchers wrote in the study. The ancient Romans likely introduced cats to Europe for this reason, according to the study.

Today, one in every three U.S. households has a pet cat, according to the study, and there are more than 600 million domestic cats worldwide.

Editor's note: This story was updated at 10:49 a.m. ET on April 30 to correct the caption of the animal bones photo. It includes both cat and rat remains, not just cat remains as was previously stated.

The domestic cat is one of the smallest members of the family Felidae — the group that includes lions, tigers, jaguars and cougars. It is also the only member of that family that has been domesticated.

Cats have lived among humans for thousands of years. They probably started hanging around human grain stores, attracted by mice and other vermin, and eventually spread around the world as sailors brought them aboard ships.

Today, cats still help humans control pests, as well as provide companionship. In the past few centuries, humans have bred some cats to display certain traits, like hairlessness, thereby establishing dozens of cat breeds. With their charming mix of aloofness and goofiness, cats continue to amuse and fascinate us.

Everything you need to know about domestic cats

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China's first pet cats arrived in the country around 1,400 years ago — likely via the famous Silk Road trading route, ancient feline DNA reveals.

This new research — hailed as a "knockout study" — places the arrival of domestic cats in East Asia several hundred years later than previous studies. And it appears that the kitties were an instant hit with the local elite.

"Cats were initially regarded as prized, exotic pets," study co-author Shu-Jin Luo, a principal investigator at the Laboratory of Genomic Diversity and Evolution at Peking University in China, told Live Science in an email. "Cats' mysterious behaviors — alternating between distant and affectionate — added an air of mystique."

Modern domestic cats (Felis catus) descend from African wildcats (Felis silvestris lybica). Previous research suggests these felines began living alongside humans in the Middle East roughly 10,000 years ago, before evolving and then spreading to Europe about 3,000 years ago, according to the new study.

Around A.D. 600, merchants and diplomats first transported domestic cats in small crates and cages from the eastern Mediterranean through Central Asia, Luo said. These traders and officials brought just a handful of the pets to China, offering them as tribute to members of the elite, she said.

Related: Lasers reveal secrets of lost Silk Road cities in the mountains of Uzbekistan

Archaeological evidence shows that long before the arrival of domestic cats in China, people in rural Chinese communities lived alongside native leopard cats (Prionailurus bengalensis). Researchers have previously found leopard cat bones dating to 5,400 years ago in an ancient farming village in the northwestern Shaanxi province, indicating that humans and cats co-existed in settlements together.

But this relationship was not equivalent to cat domestication, the authors of the new study argued. Moreover, the common assumption that cat domestication took place in China during the Han Dynasty between 206 B.C. and A.D. 220 also lacks support, as there are no archaeological remains of pet cats from that period. Therefore, a complete re-evaluation of when and how domestic cats came to China is required, the researchers said in the study.

'A highly challenging task'

To address these questions, Luo and her colleagues analyzed 22 feline remains from 14 archaeological sites in China spanning a period of about 5,000 years. The researchers first sequenced nuclear and mitochondrial DNA in the bones to determine each species. Then, the researchers compared these results with previously published data from 63 nuclear and 108 mitochondrial genomes that summarize the evolution of cat genetics worldwide.

"This is by far the largest and most comprehensive study on small felids living closely with humans in China," Luo said. "Assembling the archaeological samples of cat remains from China across this time period [was] a highly challenging task."

Fourteen of the 22 feline bones from China belonged to domestic cats, according to the study, which was uploaded Feb. 5 to the preprint database BioRxiv and has not yet been peer reviewed. The oldest of these pet cat remains originated from Tongwan City in Shaanxi and was radiocarbon dated to A.D. 730, suggesting that domestic cats arrived in China long after the Han Dynasty had ended.

The 14 domestic cats in the sample all shared a genetic signature in their mitochondrial DNA known as clade IV-B. This signature is rare among domestic cats from Europe and Western Asia, but the researchers found a close match in the previously published data about a cat that lived sometime between A.D. 775 and 940 in the city of Dhzankent, Kazakhstan.

The Dhzankent cat is the oldest-known domestic cat along the Silk Road, offering tantalizing clues about the origins of domestic cats in China. The Silk Road's heyday lasted between A.D. 500 and 800, hinting that merchants likely transported the kitties to East Asia along this route.

Rare coat colors

The cats that merchants and diplomats initially gifted to the Chinese elite were likely all-white cats or mackerel-tabby cats with white patches, the researchers noted in the study. DNA from the Tongwan City cat suggested it was a healthy male with a long tail and short, either all-white or partially white fur, they said. Even today, the proportion of white cats is higher in East Asia than elsewhere in the world, the researchers added.

Domestic cats became so popular following their introduction to China that people incorporated them into Chinese folk religion, Luo said. "Ancient Chinese people even performed specific religious rituals when bringing a cat into their homes, viewing them not as mere possessions but as honored guests," she said.

Melinda Zeder, an archaeozoologist at the Smithsonian Institution's National Museum of Natural History who was not involved in the new research, told Science magazine that the work offers valuable insights into how domestic cats made it to China. "Tying them to the Silk Road is really boffo," Zeder said. "It's a knockout study."

Researchers in China have found the remains of a cat that was so small it could have nestled in the palm of your hand. The fossils were discovered deep within a cave where early humans lived.

The pocket-size feline is a newfound species, Prionailurus kurteni, which the scientists described in a study published Nov. 19, 2024 in the journal Annales Zoologici Fennici. The researchers believe that the extinct animal, which could date as far back as 300,000 years, may be the smallest cat ever found.

The newly identified species is part of the leopard cat genus Prionailurus, a family of wild cats that still exists today in South Asia. While most modern-day leopard cats are closer in size to domestic cats — which reach average lengths of 28 inches (70 centimeters) and weigh at least 4.4 pounds (2 kilograms) — the new species was more diminutive.

"This cat is clearly smaller than a domestic cat. It is comparable to the smallest living cat, [at around] 1 kilogram [2.2 pounds]," lead author Qigao Jiangzuo, a researcher at the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology, told Live Science.

Related: 35,000-year-old saber-toothed kitten with preserved whiskers pulled from permafrost in Siberia

Today, the smallest living wild cat species are the black-footed cat (Felis nigripes) and the rusty-spotted cat (Prionailurus rubiginosus), which are about 13.7 to 20.4 inches (35 to 52 cm) and 13.7 to 18.9 inches (35 to 48 cm) long respectively. Based on the newfound species' fossilized remains, the researchers estimated that the extinct feline was roughly the same size, or possibly smaller, than both the modern-day species, estimating that it measured between 13.7 and 19.7 inches (50 cm), Jiangzuo said.

Clues to the life and size of this miniature feline came from a single, fossilized fragment of its lower jawbone, complete with two teeth, which was discovered in a palaeontological hotspot in eastern China called Hualongdong Cave.

"Cats are common elements in the Quaternary [the geological period that spans from 2.58 million years ago until today] deposit of caves. However, finding such a small cat is a surprise," Jiangzuo said.

Fossilized remains of leopard cat ancestors are rare, because these animals tend to live in unsheltered forest environments where their bones degrade more quickly, meaning few prehistoric specimens have survived. But in the protective environment of the cave, the bones of the recently discovered specimen were preserved, giving the researchers a unique opportunity to examine them.

The prehistoric leopard cat may have wandered into the cave in pursuit of rats and mice that may have been feeding on food scraps left behind by early human inhabitants that once lived in Hualongdong Cave, the researchers told the South China Morning Post.

The inclined angle of one of the mini cat's teeth also connects the prehistoric leopard cat to the common ancestor of domestic cats and a species called the Pallas's cat (Otocolobus manul). While it was already known that leopard cats share heritage with these other species, the Hualongdong Cave findings provide the first fossil evidence of that link.

According to the study, the leopard cat family is the most diverse cat genus in the southern and southeastern forests of Asia, with five living species spread across the region. The cave specimen adds valuable detail to this family history: "The new species for the first time reveals the past diversity of this genus," Jianghuo said.

This has given the researchers new data with which to investigate the origins of all cats, he added. "We plan to systematically survey the fossil cats in China and around the world, which were not well studied in the past. We hope to trace the origins and past diversity of the cat family."

Leopards, cheetahs, Egyptian maus — a variety of cats have stunning spots. Others, like tigers, have stripes; still others, like lions, lack patterns on their coats. But how do cats get their spots, specifically?

Scientists don't have a complete answer to this question, but they've uncovered many clues.

"We don't know why some cats have spots and some cats have stripes," Dr. Greg Barsh, a professor emeritus of genetics and pediatrics at Stanford University, told Live Science. But researchers have identified two genes that affect the size and shape of spots — as well as stripes — in both domestic cats and wild felines.

Domestic cats with one or two normal copies of a gene called Taqpep have stripes, Barsh and colleagues reported in a 2012 paper published in the journal Science. But according to this same paper, as Live Science previously reported, cats with mutations in both copies of this gene (one from their mother and one from their father) have fur that is blotched or whorled.

These Taqpep mutations give rise to the patterns of the classic tabby cat, Leslie Lyons, a cat geneticist at the University of Missouri College of Veterinary Medicine, told Live Science.

Related: Is it safe for cats to drink milk?

Taqpep mutations can also modify spots — at least in cheetahs. Cheetahs are known for having black spots on a yellowish-tan background. But "king cheetahs" — which have mutations in both copies of the Taqpep gene, according to the 2012 Science paper — have large, blotchy spots. Along the spine, the blotches align themselves into stripes.

Although spotted domestic cats are obviously not striped, they appear to have a normal version of Taqpep, according to Eduardo Eizirik, a professor of genetics at the Pontifical Catholic University of Rio Grande do Sul in Porto Alegre, Brazil. As part of a study published in the journal Genetics in 2010, he mated a spotted domestic cat with a blotched one.

Eizirik and his colleagues concluded that the spotted cat he started with — an Egyptian mau — must have had a normal Taqpep gene, because some of its descendants had stripes. The team also surmised that one or more other genes in the spotted cat had the effect of breaking up the stripes that Taqpep would normally cause and turning them into spots. It's still unclear what those other genes are, he said.

Another gene that seems to affect spotting is Dkk4, according to Barsh. The Abyssinian breed of domestic cat has one or two mutated copies of the Dkk4 gene. Its coat, at a glance, appears to be a solid brown or cinnamon color. Another way to view it, however, is as a coat peppered with tiny black spots, Barsh said.

Servals are wild felines with large spots, and they have two normal copies of Dkk4. Therefore, if you cross an Abyssinian cat with a serval, as has been done, some of the offspring inherit one normal copy and one mutant copy of Dkk4, Barsh explained. These offspring have spots that are larger and sparser than the peppered spots on the Abyssinian parent but smaller and more numerous than those of the serval parent.

"This is a very clear example of how the [Dkk4] gene can affect the number and the size of spots on the animal," Barsh said.

Although mutations in Taqpep and Dkk4 can modify spots and stripes, these genes do not by themselves control whether cats have spots or stripes in the first place. A tiger with a normal Taqpep gene has stripes, while a cheetah with a normal Taqpep gene has spots, Barsh said. While mutations in Taqpep can make a cheetah's spots become blotchy, the spots don't turn into stripes.

And as Eizirik's work showed, domestic cats with a normal Taqpep gene can be either striped or spotted. "There must be something else yet, a third gene, that is helping to create those spots," Lyons said.

Fetch is a game inextricably tied to dogs. But new research shows that cats play fetch, too — maybe more than you thought.

Approximately 40% of cats will bring back a thrown toy at least some of the time, according to the study, published Wednesday (Sept. 4) in the journal PLOS One. The question is, why? We know some reasons why dogs play fetch, but it's not as obvious why cats do, the study authors said.

"During the domestication of dogs, we have selected them for some specific behaviors, such as retrieving, that probably explain to a larger extent why [fetching] behavior is much more common in dogs," study co-author Mikel Delgado, an animal behaviorist at Purdue University in Indiana, said in an interview with PLOS One provided to Live Science. "To me, the bigger question is why so many cats fetch, since we have not, to our knowledge, specifically selected them to help humans with tasks like hunting or herding."

A 2023 study in the journal Scientific Reports found that cats (Felis catus) who play fetch tend to do so on their own terms, with nearly 95% of cats initiating a game of fetch without explicit training. But that study only surveyed cat owners who reported that their cats played fetch. The new study digs into just how prevalent fetching behavior is.

In a survey of more than 8,000 cat owners, the researchers found that 40.9% of cats play fetch "sometimes," "usually" or "always." And plenty of cats engage in other carrying activities, even if they don't fetch: Nearly 58% of cats carry toys around, and 39% bring their owners a toy to kick off playtime.

Siamese, Burmese and Tonkinese cats were the breeds that were most likely to play fetch. Being male, living exclusively indoors and having no health problems also increased the likelihood that a cat would fetch. And living with dogs made cats overall less likely to fetch, which might result from dogs expressing predatory behavior toward cats or their toys, the researchers suggested.

The team also looked into fetching behavior in dogs (Canis lupus familiaris). Perhaps unsurprisingly, dogs were more likely than cats to play fetch: A survey of over 73,000 dog owners found that almost 78% of dogs played fetch at least sometimes, with retrievers, poodles, pointers and spaniels most likely to engage in the behavior. Retrievers in particular — as the name suggests — were bred to "fetch" game for hunters.

Just like dogs, cats may be playing fetch for fun.

"In both species, fetching is correlated with measures of activity and energy, so it does appear to be a form of play," Delgado said in the statement. Fetching may help cats practice hunting behaviors, like pouncing and biting, the researchers suggested, though how much these behaviors have been influenced by domestication remains unclear.

"We hope that the study draws more attention to fetching behavior in cats, who are often portrayed as independent or aloof," Delgado said in the statement. "In fact, they can be very social, and this is a nice example of one way they are interactive with humans."

A one-time injection of an experimental gene therapy appears to be an effective form of birth control for felines and could help control cat overpopulation, a small study suggests. 

There are roughly 600 million cats worldwide, with an estimated 80% being feral or strays, according to the World Animal Foundation, a nonprofit that promotes animal welfare.

The shot works by delivering a gene into a female cat's muscle cells, which triggers the production of a substance called anti-Müllerian hormone. This disrupts the development of egg follicles inside the feline's ovaries, preventing ovulation, the release of mature eggs that could be fertilized, according to a study published June 6 in the journal Nature Communications. Ovulation is also associated with mate-seeking behaviors in cats.

Currently, the most commonly used forms of birth control in cats are spaying, for females, or neutering, for males, both of which are invasive surgical procedures.

"Coming up with an alternative to surgery has been a goal for a lot of people for decades, and there just hasn't been anything else that's proven to be effective," study co-author William Swanson, director of animal research at the Cincinnati Zoo and Botanical Garden, told The New York Times.

Related: Cats can memorize their friends' names, study suggests

Although the study was small, including only six females that received the shot and three that didn't, the results showed promise. Four of the treated females didn't show interest in mating with the males. Meanwhile, the two that did mate repeatedly with the males didn't ovulate and, therefore, didn't get pregnant. 

The single shot prevented pregnancy for up to two years, according to the study. 

In addition to testing the gene therapy on adult cats, the researchers tested it on mice and found the treatment to be equally effective. Next, they plan to test the treatment on kittens, which reach sexual maturity at four months of age, and dogs, according to The New York Times.

However, the researchers cautioned that the injection is several years away from becoming available as a birth control treatment for cats. They're currently planning a larger study that could serve as the basis for them to apply for approval from the U.S. Food and Drug Administration, according to The New York Times.

The team is also investigating whether one day the therapy can be applied to humans, according to the study, but they didn't provide further details. 

"This is really exciting, and I hope it will pan out," Julie Levy, a veterinarian at the University of Florida College of Veterinary Medicine in Gainesville, Florida, who was not involved with the study, told The New York Times. "Wouldn't it be great if we could send out a technician into the field to inject cats and then let them go?"

For generations, local shepherds on the Mediterranean island of Corsica have shared stories about the "ghjattu volpe," or "cat-fox," attacking the udders of sheep and goats, AFP reported in 2019. Scientists first documented their existence in 1929 and may soon be able to declare them a new subspecies after almost 100 years thanks to new genetics research. 

Corsican wildcats get their "cat-fox" nickname from their fox-like color and large tail. Despite what their nickname suggests, these animals are not cat-fox hybrids; they're definitely all cat. Corsican wildcats belong to the genus Felis alongside other wildcats and domestic cats, but researchers are studying their genetics to figure out their exact placement in the group.

Some media outlets have suggested that Corsican wildcats are a new species — Live Science reported that this was a possibility in 2019 — but that's not strictly true. A study published in the journal Molecular Ecology on Jan. 19 of this year found that Corsican wildcats might be a subspecies, or distinct group within a known Felis species.   

"We have the proof that this small cat has its own genetic identity," study co-author Sébastien Devillard, an assistant professor of evolutionary ecology at the Claude Bernard Lyon 1 University in France, told Live Science. "This is the first step for it to be recognized as a subspecies."

The French Office for Biodiversity, which was involved in the long-running study, published a statement about the January findings on March 16. 

Related: Adorable, remorseless killing machine is world's deadliest cat

Devillard and his colleagues compared genetic samples from wildcats and domestic cats on Corsica with those from the neighboring island of Sardinia and mainland Europe. They found that Corsican wildcats were distinct from European wildcats, domestic cats and, to a lesser extent, the wildcats of Sardinia. 

Corsican wildcats have fewer stripes than European wildcats and Sardinian wildcats, but questions remain about how different they are. The researchers still need to compare Corsican wildcats with Near-Eastern mainland wildcats before they can be declared a new subspecies. And even then, there may be some debate. There are several related wildcat lineages across Europe, Asia and Africa, and researchers are still deciding where each one belongs. This process is complicated further by the presence of domestic cats, which interbreed and hybridize with wildcats.

Wildcats have traditionally been grouped together under the species Felis silvestris, with most European wildcats in the subspecies F. s. silvestris and most Afro-Asiatic wildcats in the subspecies F. s. lybica. However, the International Union for Conservation of Nature now recognizes Afro-Asiatic wildcats as their own species (F. lybica). The lybica line is important for understanding domestic cats and the new Corsican wildcat research.

"Lybica is the ancestor of domestic cats, and what we think is that some lybica were introduced at a very early stage of domestication in Corsica and in Sardinia," Devillard said. This probably happened around 8,000 years ago and the wildcats have remained wild since, Devillard added. 

Corsican wildcats occupy high elevations up to around 6,500 feet (2,000 meters), and Devillard suspects they can catch fish in Corsican rivers. The researchers will continue to study the wildcats to learn more about their lives and pin down their evolutionary history.

Ever wonder how your favorite furry feline got its stripes? A new study of domestic cats has revealed which genes give felines their distinctive fur patterns and hints that the same genetics may grant wild cats, such as tigers and cheetahs, their characteristic coats.   

How cats get their stripes is a decades-old mystery in the life sciences, senior author Dr. Gregory Barsh, a geneticist at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama, told Live Science in an email. About 70 years ago, scientists began developing theories as to why and how organisms come to bear periodic patterns, like the stripes on a zebra or the squidgy segments of a caterpillar's body. 

In some animals, like the zebrafish, these patterns emerge due to the arrangement of different types of cells. "But in mammals, the skin and hair cells are exactly the same across the entire body, and the color pattern comes about because of differences in genetic activity between, say, cells underlying a dark stripe and cells underlying a light stripe," Barsh said. So the question of how cats get their stripes comes down to how and when various genes switch on in their cells and how those genes influence the animals' development. In short, it's complicated.

Related: Genetics by the numbers: 10 tantalizing tales 

But now, in a new study, published Tuesday (Sept. 7) in the journal Nature Communications, Barsh and his colleagues identified several genes that work together to give cats their coat patterns. 

One gene, called Transmembrane aminopeptidase Q (Taqpep), they'd identified previously, in a study published in 2012 in the journal Science. Cats that carry one version of the Taqpep gene end up decked out in dark, narrow stripes, while those with a mutant version of the gene bear "large whorls" of dark fur; the "whorl" version of the gene is most common in feral cats. 

To investigate what additional genes might shape the diverse markings on cats' coats, the team began collecting discarded tissue from clinics that spay feral cats; some of the resected cat uteruses contained non-viable embryos, which the researchers examined in the lab.

They noticed that, at about 28 to 30 days old, cat embryos develop regions of "thick" and "thin" skin; at later stages of development, the thick and thin skin gives rise to hair follicles that produce different types of melanin — eumelanin for dark fur, and pheomelanin for light fur. 

Remarkably, "the developmental mechanism responsible for color pattern takes place early in development, before hair follicles are formed and within cells that do not actually make any pigment but instead contribute to hair follicle structure," Barsh said. Spotting this pattern, the team examined which genes were active leading up to the development of the thick skin, to see if specific genes directed the patterns' formation.

The team found that, in 20-day-old embryos, several genes involved in cell growth and development suddenly switch on in the skin later destined to thicken and give rise to dark-fur-producing follicles. These genes are known to be involved in a "Wnt signaling pathway," a molecular chain reaction that drives cells to grow and develop into specific cell types, and one gene in particular, called Dkk4, stood out as particularly active.

Related: 20 weird dog and cat behaviors explained by science

Dkk4 codes for a protein that turns down Wnt signalling, and when it comes to cat fur, the tug-of-war between Dkk4 and Wnt seems to dictate whether a patch of fur ends up dark or light, the authors found. In the dark patches, Dkk4 and Wnt balance each other out, but in the light patches, Dkk4 beats out the Wnt.   

This finding supports a theory that computing pioneer Alan Turing developed in the 1950s, Science magazine reported. Turing proposed that animals' periodic patterns, like stripes, crop up when an "activator" molecule boosts the production of an "inhibitor" molecule, and these two molecules mingle in the same tissue; in this case, Wnt would be the activator and Dkk4 the inhibitor. Following Turing's hypothesis, Barsh's team thinks that Dkk4 spreads through tissue more quickly than the Wnt signalling travels, and that this uneven distribution generates periodic patches of light and dark in cats. 

What's more, a cat's Taqpep genotype — meaning whether it carries the "stripe" or "whorl" version of the gene — also dictates where the Dkk4 gene can be activated, Barsh said. "But we don't know exactly how that happens," he added. Taqpep codes for a protease, an enzyme that breaks down other proteins, but for now, the team doesn't know whether this enzyme affects Dkk4 activity directly or indirectly.

As a follow-up to the embryo analyses, the team examined cat genome sequences from a database called the 99 Lives collection. They found that Abyssinian and Singapura breeds, which bear no stripes or spots and instead have a uniform appearance, carry mutant versions of Dkk4 that disable the gene. In future work, the team wants to see whether similar mutations crop up in wild cats. 

Previous studies suggested that for cheetahs (Acinonyx jubatus), at least, a cat's Taqpep genotype affects the appearance of its spots, and the same might go for Dkk4, the authors noted. Then there's the serval (Felis serval), an African wild cat that usually sports bold, black spots but occasionally grows a coat of tiny, tightly packed specks instead. Could a Dkk4 mutation explain this variation?  

"Our observations to date are only on domestic cats," Barsh said. "It is quite likely that the molecules and mechanisms studied in domestic cats apply to all of the more than 30 species of wild cats, but we will need to carry out additional studies of wild cat DNA to know that for sure." 

Beyond wild cats, the team wants to study whether the same mechanisms are also at play in distantly related mammals, such as zebras and giraffes. 

Originally published on Live Science.

When Fluffy turns her nose up at the bowl of food you've placed in front of her, don't take it personally. Your seemingly high-maintenance cat has evolution to blame for her picky eating.

Cats as it turns out are driven to eat foods with a preferred ratio of protein to fat: 1 to 0.4. This translates to about 50:50 in terms of percentage of energy from protein and fat, according to the authors of a study published June 15, 2016, in the journal Royal Society Open Science.

RELATED: What Food Tastes Like to a Cat

What's more, "Cats can display neophobia," lead author Adrian Hewson-Hughes told Discovery News. "This means they are unwilling to try a food that is new or different to their normal food, which may make them appear fussy."

Prior research has found that cats and minks have almost identical food needs and foibles. Both are known as hypercarnivores, since they have evolved to eat a diet of almost exclusively meat, as opposed to omnivores like dogs. In the wild, eating a new food can lead to stomach upset or worse, making neophobia a lifesaver outside safe home environments.

To explore factors affecting cat food choices, Hewson-Hughes, a senior research scientist at the Waltham Center for Pet Nutrition, and his colleagues conducted a series of experiments.

First, they presented male and female cats with three flavors of wet foods that the researchers had formulated: rabbit, fish and orange. The foods had approximately the same protein to fat ratio. The felines favored fish, with rabbit being their second choice and orange a very distant third.

The other experiments were designed to disentangle the influences of flavor and aroma from nutrition.

"Cats initially selected food based on flavor preferences, but after 'learning' (due to prior exposure) about the nutritional composition of the foods, cats selected foods to reach a particular target balance of protein and fat regardless of added flavors," Hewson-Hughes said.

As a result, some felines actually ate more orange-flavored chow, which had the target protein to fat ratio, than they consumed fish and rabbit-flavored foods without such a precise nutrient ratio.

How cats can detect this ratio remains a complete mystery for now.

RELATED: How Catnip Gets Cats High

Martha Cline, a veterinarian specializing in clinical nutrition at Red Bank Veterinary Hospital, recently analyzed current feeding practices of cat owners for the upcoming book, "Feline Internal Medicine," directed at animal health care experts. In it she suggests that cats may not be getting enough protein in their diets, per the current National Research Council and Association of American Feed Control Officials guidelines.

"The protein requirement of adult cats to maintain lean body mass is now thought to be higher," according to Cline, who explained that cats fed a high protein diet for 2 months in a study maintained healthy lean body mass, while cats fed moderate and low protein diets did not fare as well.

Still other research finds that domestic cats perceive bitterness at the molecular level, allowing them to detect off ingredients with incredible precision. This could further help to explain why felines so often turn up their noses to particular foods and medicines.

As for why felines seem to go for carb-laden cat treats, it could be that, like junk food for humans, short-term appeal, conditioning and even boredom may come into play. Hewson-Hughes did say that treats can be fine for cats, so long the treats only make up about 10 percent of the cat's daily calorie requirements.

RELATED: Secret to Surviving Extinction? Don't Be a Picky Eater

Orange-flavored cat food will not be coming to stores anytime soon, but the new research does pave the way for different formulations containing the desired protein to fat ratio.

"First and foremost, an ideal cat food should provide complete and balanced nutrition -- providing all the essential nutrients including vitamins, minerals and macronutrients to maintain the health of your cat," Hewson-Hughes said.

"An ideal food needs the right balance of protein and fat, based on the finding of this study, and also needs to be appealing to a cat in terms of flavor, aroma and texture. We still have a lot to learn before we fully understand all the factors that influence food selection in the cat."

This article was originally published on Discovery News.

A cute and cuddly kitty cat with strange facial hair and unusual hunting habits is changing the way people think about a not-so-adorable mythological creature: the werewolf.

The Lykoi breed of domestic cat (its name comes from the Greek word lykos, or wolf) has an unusual genetic mutation that causes its hair to grow in a werewolflike way. The skin around the cat's eyes, muzzle and chin is hairless, making it resemble a human-turned-werewolf. Lykoi cats are partially hairless on their legs and paws as well, giving them a "hairy hand" appearance (the telltale sign that a person is about to shift into a werewolf), said Johnny Gobble, a veterinarian and Lykoi breeder in Tennessee.

And so-called werewolf cats don't just look like tiny, shape-shifting dogs; they also act a bit like canines, Gobble told Live Science. [Here, Kitty, Kitty: 10 Facts for Cat Lovers]

"They do act like dogs in many [ways], though they are still cats," Gobble said. When Lykoi cats get together, he added, they behave like a pack of pups, wagging their tales as they play and taking off after prey items like a "bunch of dogs hunting something."

Gobble noted that these behaviors aren't seen in all Lykoi, and that there are other breeds of cats that also have distinctly doglike traits. But generally speaking, the wolf cat doesn't behave like your average house cat. Prone to playing all day, Lykoi prefer running after things to cuddling up on the couch for hours, he said.

Strange genes

Unlike its namesake, the werewolf kitty's wolfish traits aren't caused by a magic spell; rather, they're the result of a naturally occurring genetic mutation. Gobble, who was the first person to start a breeding program for these strange-looking cats, said that geneticists have yet to determine which gene is responsible for the cat's werewolflike appearance. However, genetic tests administered by the University of California, Davis proved that the cat, which shares some characteristics with the nearly hairless Sphynx cat breed, does not share the same genes as this other breed of kitty.

Breeders also have determined that the cat's unusual hair growth patterns aren't the result of any kind of disease or infection. Dermatologists and cardiologists at the University of Tennessee performed a number of tests on the animals and ruled out this possibility, Gobble said.

The genetic mutation that causes the cat's appearance is recessive, according to Gobble, who explained that, to breed the cuddly wolf kittens, he and his wife, Brittney Gobble, adopt black domestic cats from local shelters. Then, they pair these cats up with Lykoi cats.

"All of their babies will look like normal black cats, but they carry the Lykoi gene," Gobble said. "So we can take those babies, and babies from another domestic-Lykoi [litter], and breed them together, and we will get Lykoi kittens." Moreover, the offspring of two Lykoi cats will also look like cuddly werewolves, he added.

However, Gobble avoids breeding Lykoi cats with other Lykoi cats (at least for now) because doing so decreases the offspring's genetic variability, which can result in health problems for the cats. Purebred cats (and other purebred animals) often have health issues that nonpurebred animals don't have. In cats, the most prevalent problem is a weakened immune system, which is associated with more frequent illness for these pets, Gobble said. 

So far, Gobble has not seen evidence that purposefully bred Lykoi are any less healthy than nonpurebred domestic cats. Gobble thinks part of the reason for this may be that the non-Lykoi cats he uses in his breeding program are rescued from shelters and may be feral cats with a very diverse gene pool. In the future, when the Lykoi's genetic mutation is more prevalent, Gobble said he hopes to just breed adult Lykoi with one another.

"We're trying to breed these cats for genetic variability and health before we focus on their looks," Gobble said, adding that he gets a lot of "hate email" from people who are concerned that he is breeding cats with a genetic mutation that is not yet fully understood.

"But I had a geneticist tell me once that if you want a gene breed to exist — in other words, if we want Lykoi to exist and not disappear — we have to breed them," Gobble said. Otherwise, the world might never know the cuteness of the werewolf kitty.

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

After spending decades searching for the most comfortable spot on the couch and perfecting his "come pet me" purr, one aged feline has finally earned his time in the spotlight.

Twenty-six-year-old Corduroy, a handsome male kitty from the United States, was crowned the oldest living domestic cat this week by Guinness World Records. Corduroy's title replaces another venerable cat in the record book, Tiffany Two, who died recently at the ripe old age of 27 years, 2 months and 20 days.

Corduroy's age may not seem that impressive to long-living humans, but the cat's 26 years are notable for a domestic kitty. These animals have an average life span of only 12 to 15 years, according to Franny Syufy, About.com's resident cat expert, who has been writing about cats since Corduroy was a mere kitten. [Here Kitty, Kitty: 10 Facts for Cat Lovers]

Although most pet cats die in their teenage years, it's not all that unusual for an indoor house cat to make it into its early 20s, if it's well cared for and doesn't have any serious medical conditions, Syufy said in an article for About.com.

Corduroy's owner, Ashley Reed Okura, told the Guinness World Records that she has had the cat since she was 7 years old. When Okura learned that her beloved pet was now the oldest living house cat in the world, the owner said she was "thrilled." Corduroy was likely thrilled, as well, Okura said, because she promptly bought the cat a mouse to eat in honor of his achievement.

Though the American kitty is now the oldest living cat on record, he is not the oldest domestic cat to have ever lived, according to Guinness officials; that designation belongs to Crème Puff, who lived to the awe-inspiring age of 38 years and 3 days.

Many other cats have also set Guinness World Records for their incredible characteristics. For example, the largest living cat weighs a whopping 922 lbs. (418.2 kilograms). Of course, he's no house cat: Hercules, an adult male liger (his father was a lion, his mother a tigress), lives in an animal reserve in Myrtle Beach, South Carolina. Standing a little more than 4 feet (1.2 meters) tall at the shoulder, Hercules is actually a tad shorter than his brother, Sinbad, who weighs less than Hercules and therefore missed out on the largest cat title.

And no one can overlook the awesome coat found on another incredible feline — Sophie Smith, a California kitty who holds the world record for the longest fur on a cat. Her luscious locks are an astounding 10.11 inches (25.68 centimeters) long.

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

When your cat sees a stranger, does he come and snuggle close or hiss and run away?

Whether a feline friend is a lap cat or a claws-out kitty is largely affected by their socialization as young kittens. But at least part of cats' friendliness may be in their genes. And the widespread practice of spaying or neutering cats before they are adopted may be inadvertently selecting for aloof cats, by ensuring the friendliest animals don't reproduce, one researcher says.

"The very cats that are the friendliest and the ones that don't do much hunting are the very ones we are told we should be neutering," said John Bradshaw, an anthrozoologist at the University of Bristol in England, and the author of "Cat Sense: How the New Feline Science Can Make You a Better Friend to Your Pet" (Basic Books, 2013). [6 Secrets to Unlock Your Cat's Personality]

But not everyone is convinced.

Domestic and feral cats are genetically indistinguishable, so spay/neuter programs are unlikely to nudge the gene pool one way or the other, said Carlos Driscoll, a University of Oxford biologist who is studying the genome of the wildcat from which the domestic cat emerged at the National Institutes of Health in Bethesda, Md.

Subtle differences

Domestic cats arose from a subspecies of cat called Felis silvestris lybica between 10,000 and 20,000 years ago in the Near East or North Africa. But the genetic differences between this wildcat ancestor and its tamer offshoot are very subtle: Wild cats and domestic cats look alike and are able to mate with one another, Driscoll said.

Just 10 to 20 gene changes may be responsible for domestication in the tame cats, though scientists don't know which ones.  

Because so few genes are associated with domestication, spay and neuter policies that ensure the friendliest cats don't reproduce could be "pushing domestication backward" to a noticeable degree in the next 50 to 100 years, Bradshaw told LiveScience.

Selecting for less-friendly cats?

To support that notion, Bradshaw conducted a simple test of cat personality in Southampton, England: He had strangers enter the houses of kittens in the area, try to pick up and stroke the cats, and then watched the kitties purr or hide.

In an area where spaying and neutering rates were highest — more than 98 percent —kitties tended to be a bit more skittish around strangers, possibly because they have to "import" their fluffy friends since their own pals aren't able to reproduce. Less-affluent areas had bolder, friendlier cats. [Images: See How Cats See the World]

"What we suggest is people [in affluent areas] are getting kittens in from the countryside from feral cats that are a little bit wilder," or from a few feral females and just a few tomcats that are "living in the shadows," Bradshaw said.

Therefore, intensive spay and neuter programs may be artificially selecting for the less-tame cats, he said.

"Neutering is — in terms of biology, in terms of population dynamics — a mortality factor," Bradshaw said. "If you neuter, you've removed its genes from the pools, so when you look at the next population, you have to rule it out."

The study has a few caveats: It hasn't been published in a peer-reviewed journal, and the team only looked at about 70 cats in all.

Other solutions

And even if the findings are borne out, Bradshaw isn't suggesting a return to the old days, when cats mated freely and the unwanted kittens were tossed in a sack and drowned.

Cats kill billions of animals a year, so cities rightly want to keep feral-cat colonies in check. But if that's cities' aim, Bradshaw said, they should find the ultimate source of the problem: food.

"Are there people feeding them, are they stealing the food, is it bad hygiene in restaurants?" Bradshaw said.

Reduce the available food, and the feral-cat population will naturally decrease, he said.

Identifying the genes involved in cat personality could also help, by allowing breeders, for the first time, to select for traits such as friendliness and gentleness, rather than just looks, he said.

Skeptics remain

Driscoll doesn't think spay and neuter programs will make cats any less friendly. For one, no studies have ever shown any genetic differences between house kitties and feral cats — which are, after all, just domestic cats that fend for themselves and haven't been socialized to live with humans.

Moreover, simply too many cats with too much freedom are on the prowl for spay and neuter programs to change the entire gene pool.

"The population of domestic cats has been stable for a very long time," Driscoll said. "There's a lot of genetic inertia there. You can go out and spay and neuter all the damn cats you want, and the next year, they're all going to be back."

Follow Tia Ghose on Twitter and Google+. Follow LiveScience @livescience, Facebook & Google+. Original article on LiveScience.

Domestic cats have been traced back to a single wild ancestor whose relatives still live in the remote deserts of the Middle East today.

The transformation of a vicious predator into a docile tabby took place some 10,000 years ago, a new genetic analysis suggests. That is the same time humans adopted an agricultural lifestyle in the Fertile Crescent. So the first of the friendly cats likely acted as a mouse hunter for grain-storage areas.

“We think that was the beginning of one of the most interesting natural history experiments ever done,” said Stephen O’Brien, a geneticist at the National Cancer Institute in Maryland, “which is the changing of a wild, ferocious predator into a friendly mouser that decided to hang its wagon on humankind.”

Until now, scientists knew close to nil about the genetic relationships between different types of cats, including wild versus domestic varieties.

Well-kempt housecats can and often do breed with wild species, which has made it tricky for scientists to distinguish between a hybrid wild-domestic feline and a purely wild or house variety.

Kitty genes

The key difference between the two is behavior. Domestic cats can live in groups and are generally not afraid of people. Since behavioral analyses of a large and diverse group of cats would be nearly impossible, an international research team turned to genetics.

Carlos Driscoll of the National Cancer Institute and his colleagues analyzed genetic material from nearly 1,000 cats, including domestic cats and the wild cat subspecies: the European wildcat, Near Eastern wildcat, Central Asian wildcat, southern African wildcat and Chinese desert cat.

They found that each wild group represents a subspecies of the wildcat Felis silvestris. The DNA from domestic cats matched up with that of the Near Eastern wildcat subspecies Felis silvestris lybica, which lives in the remote deserts of Israel and Saudi Arabia.

They detail the results this week in the online version of the journal Science.

Feline family

The lineage that includes the domestic cat and its wild relatives originated earlier than previously thought, about 130,000 years ago.

The cats probably took two separate routes out of the Middle East, the scientists speculate. One group trekked to Egypt while the others traveled from Mesopotamia to India, then to China and much later made their way to Japan.

As to when domestic cats popped onto the scene, Driscoll said they don’t have the information to make a valid estimate.

To solve that puzzle, scientists are turning to written historical records and archaeological evidence. For instance, Egyptian tomb paintings indicate that by 3,600 years ago domestic cats were living in Egypt, Driscoll said. And a cat and human burial site dating back 9,500 years was unearthed in Cyprus recently.

A possible boon to this puzzle, O’Brien mentioned, is the completion of the cat genome. O’Brien and his colleagues sequenced and characterized the genetic material from a domestic cat named Cinnamon living in Columbia, Missouri. They hope to find specific genes related to cat tameness.

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