Which of the following is a characteristic of drywood termites?

Drywood termites are known for their particular nesting habits, which set them apart from other types of termites. One key characteristic is that they construct their nests within the wood itself, which serves both as a food source and a living environment. This behavior allows them to establish colonies that can thrive independently of soil moisture, unlike subterranean termites, which typically rely on soil for nest construction.

Nesting within the wood also means drywood termites can be found in a variety of wooden structures and materials, making their detection often more challenging. Their ability to live and reproduce entirely within the wood aids in the structural damage they can inflict over time.

The other options do not accurately depict the behavior or characteristics of drywood termites. They do not typically nest in soil, nor are they known for feeding on foam insulation. Additionally, drywood termites are known to swarm primarily during the day, particularly in warmer climates, which further clarifies why option C is the correct choice.