What indicates an active infestation of wood-destroying pests?

The indication of an active infestation of wood-destroying pests primarily relies on the presence of pests that are currently causing damage. This means that the correct choice clearly highlights that the detection of pests actively damaging wood structures confirms their presence and activity, which is crucial for understanding the severity of an infestation.

Identifying pests currently causing damage allows pest control professionals to assess the extent of the problem and take appropriate actions to mitigate further harm. The active signs may include fresh frass (wood dust) or newly damaged wood, indicating that the pests are not only present but also engaging in behavior that compromises structural integrity.

In contrast, the presence of pests that are not currently causing damage or no signs of pests at all do not provide evidence of ongoing or active infestations. Similarly, an inactive infestation that has been previously reported does not reflect an active problem, as it suggests that the pests are no longer present or affecting the structure. Therefore, recognizing the active activity of pests is essential in diagnosing infestations effectively and formulating an appropriate pest control strategy.