What is a distinctive feature of damage caused by old house borers?

The distinctive feature of damage caused by old house borers is the bullet hole shape. This characteristic is notable because it reflects the way these pests exit the wood after their larval stage. When old house borers infest wood, they create small, round exit holes that resemble bullet marks, which is a clear indicator of their presence and can help in identifying the type of wood-destroying insect causing the damage.

The bullet hole shape is especially significant because it differentiates old house borers from other wood-destroying insects that might create different exit patterns or signs of damage. Understanding this distinctive feature is crucial for pest control professionals in diagnosing an infestation accurately and determining the best course of action for treatment and prevention.