What infestation level is indicated by old droppings and gnawings with rats seen at night but not during the day?

• A. Low rat infestation
• B. Medium rat infestation
• C. High rat infestation
• D. Severe rat infestation

Answer: (B)

Interpreting signs of rodent activity is how we estimate infestation level. Old droppings show rats have been around for a while, and gnaw marks indicate ongoing feeding and damage. Rats that are seen at night but not during the day suggest a population that is present and active but not abundant enough to forage openly in daylight. In a low infestation, you’d expect few signs and rare sightings. In a high or severe infestation, you’d likely see more fresh droppings, heavier gnawing, and sometimes daytime activity or obvious damage. The combination described—old droppings and gnawings with nocturnal sightings but no daytime sightings—fits a moderate, or medium, level of infestation.