What type of evidence do inspectors look for during an inspection for rodent activity?

Inspectors look for urine streaks under black light as a key indicator of rodent activity due to several important factors related to rodent behavior and biology. Rodents, such as mice and rats, leave behind urine and droppings as they navigate their environment. When urine is exposed to ultraviolet (UV) light, it fluoresces, making it visible even in areas that may not be easily inspected otherwise. This method allows inspectors to quickly identify potential infestations, enabling them to assess the severity of rodent presence and take appropriate actions.

In addition to being a reliable sign of rodent activity, the presence of urine can help inspectors determine which areas are frequently trafficked by rodents, guiding their further investigation. This technique is particularly useful on ships, where maintaining cleanliness and preventing pest activity is critical for sanitation and health standards.

The other types of evidence listed may not specifically confirm current rodent activity. While predator insects can indicate a pest problem, they do not directly relate to rodent presence. Nesting sites in cargo may suggest prior activity, but do not provide definitive proof of ongoing issues. Environmental cleanliness ratings reflect overall sanitation but do not provide specific information about rodent activity. Therefore, the visibility of urine under black light is the most direct and