How can an environmental public health professional determine the types of active rodent infestations present?

Identifying mice or rat droppings is a key indicator of active rodent infestations. Rodent droppings are commonly found in areas where rodents nest or travel, and they vary in size and shape depending on the species. For instance, mouse droppings are small and pointed, while rat droppings are larger and more blunt. The presence of fresh droppings indicates recent activity, which is crucial for determining the severity and location of the infestation.

Additionally, droppings can provide insights into the types of rodents present, as different species leave distinct droppings. This identification can guide targeted control measures. Observing the property occupants, watching rods' behavior, or measuring noise levels might provide ancillary information, but these methods are less direct and may not yield definitive evidence of an active infestation compared to the physical signs left by the rodents themselves.