Risks
for Norway Rat
Norway rats pose health, property, and food-safety risks at once. Both UC IPM and CDC document that rats transmit serious diseases to people. UC IPM names typhus, leptospirosis, rat-bite fever, and foodborne illnesses from pathogens such as Salmonella, E. coli, and Campylobacter. CDC, which covers human disease transmission, also lists salmonellosis, hantavirus, and plague — spread directly through contaminated food or contact with rat urine, droppings, and bites, or indirectly through fleas and mites that feed on rats. Source: https://ipm.ucanr.edu/home-and-landscape/rats/pest-notes/ Source: https://www.cdc.gov/healthy-pets/rodent-control/index.html
For property, burrowing can undermine foundations and slabs, and rats gnaw wood, wiring, plastic, and even soft metals, shredding insulation for nests. For food safety, rats eat and contaminate stored food; one rat can eat about 30 pounds of grain a year and foul ten times that much with urine, feces, and hair. Source: https://ipm.ucanr.edu/home-and-landscape/rats/pest-notes/ Source: https://extension.missouri.edu/publications/g9446