Kittens may purr when they drink their mother's milk. Later in life, purring is often used as a greeting. Cats also purr when they are happy, even while they eat. A cat can purr when it is hurt, hungry or nervous.
For about half a century, scientists thought a purr needed the muscles of the voice box to tighten and relax in a steady rhythm, with the brain giving constant orders. In 2023 a study in Current Biology reported that cat voice boxes taken from cats that had died could make purr-range sounds when air was blown through them, with no brain signals and no muscle action. The way a cat's voice box makes a purr is strikingly like human creaky voice, also called vocal fry. The researchers said their findings do not completely disprove the muscle idea, but show that the current understanding of purring is incomplete, as of November 2026. Because cats rest so much to save energy, one proposal is that purring is a low-energy way to keep muscles and bones working. A 2003 Scientific American answer called this only possible.
Cats can make a special urgent purr when they want food. A cry or meow is tucked inside an otherwise soft, low purr. In a University of Sussex study, listeners who had never owned a cat still rated the purrs cats made when asking for food as more urgent and less pleasant than purrs made at other times.
In the 1800s, scientists split cats into two groups: small cats that could purr but not roar, and big cats that could roar but not purr. Big cats such as lions, tigers, leopards and jaguars have a partly bony hyoid and a flexible larynx that let them roar.
In 2017 researchers studied DNA from about 230 ancient and modern cats from Europe, Africa and southwest Asia. The cats covered around 9,000 years, and the aim was to trace where house cats came from. They used DNA from bones, teeth, skin and hair of over 200 cats found at archaeological sites, between 100 and 9,000 years old. Skeletons of the five wildcat subspecies look the same as a house cat's, so scientists could not tell which was tamed by looking at bones and used DNA instead.
The domestic cat's DNA traces back to a wildcat called Felis silvestris lybica, which lives in North Africa and the Near East. The 2017 DNA study found that both Near Eastern and Egyptian wildcats helped form the house cat's gene pool, at different times, in two major waves. Bones of cats with an Egyptian genetic signature have even been found at Viking sites near the Baltic Sea.
The patterns of where and when cats appear suggest they spread along human sea and land trade routes. Cats later spread across Europe and elsewhere through Egypt, a trade hub, and on ships they were used to fight vermin.
Cats may have domesticated themselves. Wildcats chose to stay near farming settlements, where there was food and shelter, and people tolerated cats that kept pests away. People domesticated dogs by breeding for traits they wanted, but house cats mostly evolved through natural selection, as friendlier, calmer cats did better close to people. Scientists say cats are not as domesticated as dogs, which genetic evidence suggests were domesticated between 14,000 and 30,000 years ago.
In 2013 researchers reported small cats hunting grain-stealing rodents around a farming village in central China about 5,300 years ago. The oldest known cat burial is in Cyprus, where a person and a cat were buried together 9,500 years ago.
Words to know
- purr: soft cat hum
- vocal: of the voice
- subspecies: wildcat kinds
- archaeological: about old remains
- domesticated: tamed over generations
