Rats are complex, but researchers are working to gain a better understanding of them

Norway rats (Rattus norvegicus) are also known as brown rats, sewer rats, street rats, wharf rats and, in general, major pests. Photo: MriyaWildlife/iStock / Getty Images Plus/Getty Images

Dr. Jason Munshi-South, ecologist and professor of biodiversity, earth and environmental science at Drexel University, started studying rodents in New York City more than a decade ago and was mainly interested in native animals, specifically white-footed mice (Peromyscus leucopus). But he found many New Yorkers he encountered during his fieldwork were more interested in hearing about another rodent, rats.

So Dr. Munshi-South set out to answer what seemed like a pretty basic question: “What is a New York City rat? Where did they come from?”

The answer, he found, was complicated, according to a story by NPR. The history, evolution and ecology of rats – particularly the Norway rat (Rattus norvegicus) – isn’t well understood.

In a new paper published in the journal Science, Dr. Munshi-South and other researchers wrote that with advances in genomics and paleoarchaeology – the study of ancient humans – that’s about to change.

“I think we’re kind of at this cusp of a deluge of information about rats coming from these two fields,” he said.

Information could help scientists understand the first time humans and rats started commingling in East Asia, beginning – for the rats, at least – what would become one of the most successful partnerships in the world. Information could also further illuminate parts of human history like ancient trade corridors and human migrations. Rats have been traveling with and beside humans for thousands of years.

The paper is one of three rat-focused reviews published in a special issue of Science aimed at better understanding what it calls “our perennial rodent companions.”

The other reviews address emerging patterns in diseases that are able to jump from rodents to humans and a growing understanding, in the scientific community, of how intelligent and empathetic rats are. Studies have shown that rats in laboratory settings will help each other when they’re in distress, raising ethical concerns about their treatment in research.

“We have treated rats and the problems associated with them as a really simple issue. We see a rat, we don’t like it, we kill a rat,” said Dr. Kaylee Byers, an assistant professor at Simon Fraser University, who was one of the presenters at the inaugural National Urban Rat Summit that took place in New York City Sept. 18-19. “But rats and issues associated with them are incredibly complex.”

To manage them, she said, “We need to not only understand the rat, but we actually also have to understand ourselves and our relationship to rats in order to move towards a healthier coexistence.”