This article is from the WSSF 2016 AFRMA Rat & Mouse Tales news-magazine.

In a study done in Baltimore, MD, scientists from the Johns Hopkins Bloomberg School of Public Health, found that wild Norway rats (Rattus norvegicus) form communities of about 11 city blocks that are further divided into smaller neighborhoods about the size of an average alley. Rats in these neighborhoods rarely ventured more than a city block, but stayed close to their homes where they spend most of their lives. The rats would, however, travel up to 7 miles to repopulate abandoned areas.

Article City Rats Are Loyal To Their Neighborhoods on ScienceDaily.