What rodent sign most indicates a current infestation with rats?

The presence of soft, dark rat droppings ranging from 3/8 inch to 3/4 inch is a strong indicator of a current rat infestation. Fresh droppings that contain moisture and are dark in color typically signify that rats are actively feeding in the area. The size of the droppings is also a key characteristic, as these measurements are consistent with those produced by common rat species, such as the Norway rat and the roof rat.

In contrast, while extensive gnawed wood may suggest past activity, it does not provide definitive evidence of a current infestation, as it could also result from occasional or historical problems. Rat poisons in corners of restaurant kitchens indicate attempts to manage or control a rodent issue but do not necessarily mean rats are currently present. Similarly, the presence of burrows can suggest a rat population, but without other signs of recent activity, such as fresh droppings, burrows alone do not confirm a current infestation. Fresh droppings are the clearest and most immediate sign of ongoing rat activity in any given area, making them critical for assessment and response in pest management.