By Dr. Becker
Today many people view house mice as pests, but it wasn’t always this way. It wasn’t long ago, relatively speaking, that mice were viewed with indifference instead of disgust.
New research shows, in fact, that they’ve been living commensally with humans, meaning they derive benefit from humans while humans are unaffected, for far longer than was previously thought.
The study, published in Proceedings of the National Academy of Sciences, revealed that mice have been living alongside humans for as long as 15,000 years. This is about 3,000 years earlier than the start of crop agriculture — the time it was long believed mice took up residence with humans.
Instead, it turns out that mice made homes alongside their human neighbors during the hunter-gatherer era, as soon as humans started to put down some more permanent roots.
Wild Mice Battled Over Territory for Centuries
About 15,000 years ago, both the common mouse (Mus musculus domesticus) and the short-tailed Macedonian Mouse (Mus macedonicus) were living among the pre-farming Natufian people, a semi-sedentary society that was transitioning from hunter-gatherers to a more sedentary lifestyle.
As the people built more permanent structures, the two types of mice battled over the territory. Eventually the common mouse, which we think of as the house mouse today, won. Gizmodo reported:1
“Mice began to appear as a distinct lineage somewhere between Iran and India, sometime in the last 100,000 years. These rodents had to make an ‘honest’ living, scouring the landscape for grains, fruits and seeds.
Back then, the species that would eventually become the common house mouse was likely extremely rare, having to compete with rival species and fending of predators.
The introduction of human settlements 15,000 years ago dramatically altered the landscape for these highly adaptable mice, both literally and figuratively.”
Study co-author Lior Weissbrod, Ph.D., a research fellow at the Zinman Institute of Archaeology at the University of Haifa, further told the news outlet that while mice were benefitting from living near humans, the humans were “neither benefitting nor being harmed.”
It wasn’t until the age of agriculture that humans began to view the furry creatures as pests.
Even in the modern day, the Maasai villagers in Africa, whom the researchers also visited, still hold no ill feelings toward mice, which makes sense since they are not an agricultural society.2
Mouse Populations Used to Track Ancient Humans’ Patterns of Movement
An interesting outcome of the study was that researchers were able to use their knowledge of Natufians’ ways of life to track changes in the mice communities.
Now that the connection has been established, ZME Science noted, mice could be used to uncover more about shifts in ancient humans’ mobility and lifestyles. Weissbrod continued:3
“These findings suggest that hunter-gatherers of the Natufian culture, rather than later Neolithic farmers, were the first to adopt a sedentary way of life and unintentionally initiated a new type of ecological interaction — close coexistence with commensal species such as the house mouse.
The human dynamic of shifts between mobile and sedentary existence was unraveled in unprecedented detail in the record of fluctuations in proportions of the two species through time.”
Are House Mice Really Pests?
According to the Illinois Department of Public Health (IDPH), “The house mouse is considered one of the most troublesome and economically important pests in the United States.”4
The problem is that house mice may eat human or pet food and contaminate countertops and other surfaces with their potentially salmonella-containing feces. Mice may also carry a number of other zoonotic diseases.
They may also gnaw through wiring or other structures, and, because they can fit through openings that are about 1/4-inch wide (about the width of a pencil or dime), they gain easy access to many homes.
However, if you find a mouse in your attic or shed, you needn’t necessarily be alarmed. As the Humane Society of the United States (HSUS) put it, “House mice, like all animals, like to stay warm and fed, and often spend their lives comfortably inside buildings without causing any problems.”5
If you decide to remove mice from your home, live traps are the only humane option. Glue traps and snap traps cause significant suffering to the animals, as do poisons, which also pose a risk to your pets. If you set out live traps, be sure to check them at least once a day.
Mice should then be safely released, ideally to another indoor location, as according to HSUS, “House mice and rodents that have lived in buildings for their entire lives will have a slim chance of surviving outdoors. If possible, relocate mice to an outbuilding like a shed or garage.”6
If this sounds strange, consider that mice are deserving of compassion too, and while you certainly don’t want to invite them into your kitchen, remember that they’ve been living alongside humans, with little consequence, for thousands of years.
It’s even been found that mice communicate using ultrasonic vocalizations that carry some similarities to human speech. Erich Jarvis, Ph.D., an associate professor of neurobiology at Duke University and a Howard Hughes Medical Institute investigator, told Live Science:7
“The mouse brain and behavior for vocal communication is not as primitive and as innate as myself and many other scientists have considered it to be… Mice have more similarities in their vocal communication with humans than other species like our closest relatives [chimpanzees].”