The phrase points to a scenario where rodent infestation has occurred within a residential property. The presence of Rattus norvegicus or Rattus rattus within a dwelling constitutes a potential health hazard and property damage risk. Evidence may include droppings, gnaw marks, or actual sightings of the animal.
Addressing such an event is critical for maintaining sanitation and preventing disease transmission. Rodents can carry pathogens, contaminate food sources, and damage structural components through their nesting and feeding behaviors. Historically, rodent infestations have been linked to outbreaks of serious illnesses, emphasizing the need for prompt and effective control measures.