What type of signs do Norway rats commonly leave behind?

Norway rats commonly leave behind black pellets, which are a key indicator of their presence in an area. These droppings can provide vital information about the level of infestation and the behavior of the rats. The size and shape of the pellets can help distinguish them from those of other rodents. Generally, the black pellets are about 1/2 inch long and have a blunt end. Monitoring these droppings is essential for effective pest control and understanding the extent of the infestation, as they can indicate where rats are feeding and nesting.

The other options, such as colorful fur remnants, bright shells, or visible fur clumps, do not accurately represent the evidence left behind by Norway rats and are not typically used as identifiers for their presence. Focusing on the droppings allows pest control professionals and food safety experts to take appropriate actions in addressing rat infestations effectively.