Which of the following is not a sign of rodent infestation?

Decaying vegetables are not specifically a sign of rodent infestation, as they can result from various factors such as improper storage of food, excess moisture, or simply being past their shelf life. While rodents may indeed be attracted to decaying vegetables as a food source, the presence of these vegetables alone does not indicate that rodents are present or have been present in the area.

In contrast, fresh droppings, footprints in dust, and gnaw marks on food are all direct indicators of rodent activity. Fresh droppings suggest recent rodent presence, and footprints can indicate movement within a space, often leading to nests or food sources. Gnaw marks on food demonstrate that rodents have actively been feeding, revealing their presence and behavior in that environment.