Dogs were the first domesticated animal, but they may not have been the first to mooch off humans. Scientists previously believed mice started congregating around farms to snatch grain about 12,000 years ago. But new research out of Israel's University of Haifa suggests mice were interacting with humans in the region that is now Israel, Lebanon, and Syria, some 3,000 years before the dawn of agriculture and before domesticated dogs appeared, per the BBC. Researchers say fossil mouse teeth at archaeological sites of the Natufian culture of hunter-gatherers suggest the number of common house mice around humans increased as once-nomadic humans started to settle in one area and build houses 15,000 years ago, reports National Geographic. But the number of short-tailed mice—a species that is wilder and less tolerant of humans—dwindled.
House mice were essentially out-competing the others, eating the food the newly sedentary Natufian people stored. When sites were occupied by humans, the mouse population was about 80% house mice and 20% short-tailed mice. Only when the Natufians moved on did the proportion of short-tailed mice in the area increase. The study author tells Gizmodo the house mice weren't exactly "domesticated" as they offered no benefit to humans. However, the research shows "we've been changing them and they've been changing us" for a very long time. Adds a researcher, "Thanks to this relationship, house mice have colonized almost every corner of the globe to become almost as ubiquitous as humans." One researcher notes that the study offers a "new, detailed window" into the shift from hunter-gatherer societies to more sedentary societies. (A recent study probed the origin of dogs.)