Which of the following is NOT a common sign of a pest infestation?

Frequent buzzing sounds are not typically associated with common signs of a pest infestation. While some pests, such as flies or wasps, may make buzzing noises, this sound is not universally indicative of an infestation like the other options are. The presence of gnaw marks, droppings, and visible damage to food packaging are well-established signs that pests are present.

Gnaw marks can indicate rodents' presence, as they often chew on surfaces to access food or create nesting sites. Droppings are another key sign since they can reveal the type of pest in a home (e.g., rodent droppings versus insect droppings) and the level of activity. Visible damage to food packaging is also a major indicator of pests, particularly from insects such as pantry pests and rodents that invade food stores.

In contrast, while buzzing sounds might raise suspicion of certain flying insects, it does not serve as a reliable indicator of a pest issue on its own compared to the concrete evidence provided by the other signs.