The Natural History of the Cat
Did you know that just 60 years ago, few cats lived entirely indoors at all? In fact, for more than 10,000 years, cats have lived outdoor lives, sharing the environment with birds and wildlife. Understanding cats’ place in history and human evolution reveals how very recently domestic cats came indoors and how millions of this species—feral cats—continue to live healthy lives outdoors today, as all domestic cats are biologically adapted to do.
Origins of the Domestic Cat
Cats began their unique relationship with humans 10,000 to 12,000 years ago in the Fertile Crescent, the geographic region where some of the earliest developments in human civilization occurred (encompassing modern day parts of West Asia). One such development was agriculture. As people abandoned their nomadic lifestyle and settled permanently to farm the land, stored grain attracted rodents. Taking advantage of this new, abundant food source, Middle Eastern wildcats, or felix silvestris lybica, preyed on the rodents and decided to stick around these early towns, scavenging the garbage that all human societies inevitably produce—just as feral cats do today.
Over thousands of years, a new species of cat eventually evolved that naturally made its home around people: felis catus. Today, pet, stray, and feral cats belong to this species that we call the domestic cat.1
Cats Travel the World
Cats formed a mutually beneficial relationship with people, and some scientists argue that cats domesticated themselves.2 Especially prized as mousers on ships, cats traveled with people around the globe:
- A burial site in Cyprus provides the first archaeological evidence of humans and cats living side-by-side, as far back as 9500 BC. Cats must have been brought to the island intentionally by humans.3
- In ancient Egypt, cats were worshipped, mummified, and—artwork suggests—kept on leashes as part of the cult of the goddess Bastet.
- In 31 BC, Egypt became a province of the Roman Empire. Cats were introduced into Roman life, becoming truly widespread in Europe around the 4th century AD.4 A cat skeleton from this period shows the shortened skull of domestic cats today.5
- From Europe, cats boarded ships to the Americas, reportedly tagging along with Christopher Columbus, with the settlers at Jamestown, and aboard the Mayflower.
- In Europe, Sir Isaac Newton is rumored to have invented the cat door in the late 17th or early 18th century.
- Cats continued their service as mousers throughout history, even serving as official employees of the United States Postal Service as late as 19th and early 20th century America.6
- Towards the end of the 19th century, more Americans began to keep cats for their company as well as their utility. The first cat show was held at Madison Square Garden in 1895. By the end of World War I, cats were commonly accepted as house pets in the U.S.
Throughout all this time, cats were allowed to come and go freely from human households—even President Calvin Coolidge’s cat had free rein to wander to and from the White House during the 1920s. As Sam Stall, author of 100 Cats Who Changed Civilization and The Cat Owner’s Manual, writes, “Back in Coolidge’s day no one thought of confining cats indoors—not even one belonging to the president of the United States.”7
Catering to Cats: Inventing the Indoor Cat
Keeping cats indoors all the time was not possible—nor was it even a goal—until several important 20th century innovations: refrigeration, kitty litter, and the prevalence of spaying and neutering.
Even though these changes to our modern lifestyle make keeping cats inside possible, biologically, cats are the same as they were thousands of years ago. Their role in our society has evolved and broadened over the last hundred years, but their basic behaviors and needs haven’t changed.
Unlike dogs, who have undergone many physical changes since domestication and evolved to survive on an omnivorous diet, cats haven’t changed much, and still require a high-protein diet. Before the development of refrigeration and canned cat food in the 20th century, feeding indoor cats who could not supplement their diets by hunting would have been impossible for most Americans, who could not afford extra fresh meat or fish.8
Up until the 1950s, cats roamed American neighborhoods freely, using the great outdoors as their litter area. Pans filled with dirt or newspaper were used indoors by a few cat owners, but it wasn’t until the first clay litter was accidentally discovered in 1947 and the subsequent marketing of the Tidy Cats® brand in the 1960s that litter boxes really caught on. With the invention of cat litter, cats rocketed to popularity as indoor pets, but their outdoor survival skills remain.9
Spaying and Neutering
Until spaying and neutering pets became available and accessible around the 1930s, keeping intact cats indoors was messy business during mating season. Techniques had been developed for sterilizing livestock, but American households would have had a hard time finding a veterinarian trained to safely neuter pets before this time.10 Just as cats found their own food and litter areas outdoors, 20th century cats bred and gave birth outdoors as they have done since their origins in the Fertile Crescent 10,000 years ago. While some of those cats’ offspring have since been brought indoors through neutering and other modern developments, many cats stayed outside, living the same outdoor lives they always have, with or without human contact. Although adult feral cats—cats that are not socialized to people—cannot become indoor pets, neutering and returning them to their outdoor home improves their lives.
Cats are Part of Our Environment
In the thousands of years that cats have lived alongside people, indoor-only cats have only become common in the last 50 or 60 years—a negligible amount of time on an evolutionary scale.
Throughout human history, cats have always lived and thrived outside. It is only recently that we have begun to introduce reproduction control like spaying and neutering to bring them indoors. And also, bring the outdoors to them: using canned food and litter boxes to satisfy biological needs developed over thousands of years of living outdoors.
Although human civilization and domestic cats co-evolved side by side, the feral cat population was not created by humans. Cats have lived outdoors for a long time—they are not new to the environment and they didn’t simply originate from lost pets or negligent pet owners. Instead, they have a place in the natural landscape.
 Driscoll, Carlos A. et al. “The Taming of the Cat.” Scientific American (2009): 71-72.
 Donalson, Malcolm Drew. The Domestic Cat in Roman Civilization. The Edwin Mellen Press, Lewiston, New York: 1999.
 Weir, Harrison. Our Cats and All About Them. Fanciers’ Gazette, London: 1892.
 Stall, Sam. 100 Cats Who Changed Civilization. Quirk Books, Philadelphia: 2007.
 Bradshaw, John W.S., The Evolutionary Basis for the Feeding Behavior of Domestic Dogs (Canis familiaris) and Cats (Felis catus), 136(7) J Nutrition (2006).
 Rainbolt, Dusty. “The Best Idea,” Cat Fancy. (August 2010): 30-31.
 Grier, Katherine C. Pets in America: A History. University of North Carolina Press, Chapel Hill: 2006.