Cats and humans may have been introduced by small rodents.

Researchers believe early cats were attracted to farm regions because of the large population of rodents that were feeding off of the locally grown grain, a Washington University in St. Louis news release reported.

"Results of this study show that the village of Quanhucun [in China] was a source of food for the cats 5,300 years ago, and the relationship between humans and cats was commensal, or advantageous for the cats," Fiona Marshall, PhD, a professor of archaeology in Arts & Sciences at Washington University in St. Louis said. "Even if these cats were not yet domesticated, our evidence confirms that they lived in close proximity to farmers, and that the relationship had mutual benefits."

The origin of the common housecat has been a mystery to scientists because feline bones are almost never found in archaeological sites.  

Researchers have theorized that cats were domesticated in ancient Egypt about 4,000 years ago, but new research suggests this may have happened much earlier.

The remains of a 10,000 year old wild cat were found buried with ancient human remains in Cyprus, but there is no other evidence of domestication from this region and time frame. 

Researchers performed radiocarbon dating on the bones of "cats, dogs, deer and other wildlife unearthed near Quanhucan."

They determined these ancient wildcats may have had a "niche" in society that was linked to grain farming and rodent infestations. 

Carbon isotopes in the Quanhucan bones showed that dogs, pigs, and rodents regularly ate grain millet, but deer did not. The cats' remains suggested they were eating animals that fed on the grain millet, such as rodents.

The team found many grain-storage pots from the era had a "rodent-proof design," indicating there was a vermin problem.

The team noticed some ancient Quanhucan cats were too old to have survived in the wild without human assistance. Their isotope compositions also suggested they were fed on human scraps instead of rodents.

According to DNA analysis most modern house cats descended from the Near Eastern Wildcat. The researchers are not sure if the Quanhucan cats had the same ancestor.

"We do not yet know whether these cats came to China from the Near East, whether they interbred with Chinese wild-cat species, or even whether cats from China played a previously unsuspected role in domestication," Marshall said.