What is unique about the way subterranean termites eat wood?

Subterranean termites have a distinctive feeding behavior that involves consuming wood between the grain rather than across or with the grain. This method allows them to efficiently exploit the cellulose within the wood, which is their primary food source. By eating along the grain, they are able to gain access to the softer portions of the wood, which helps them to digest it more effectively. This behavior not only optimizes their feeding but also minimizes the exposure of the wood's surface, allowing them to remain hidden from predators and environmental threats.

The other choices reflect behaviors that do not accurately describe subterranean termite feeding habits. For instance, subterranean termites do not exclusively consume dry wood; they thrive on a range of wood content levels, including damp and decayed wood. Additionally, they do not digest wood whole but instead utilize symbiotic microorganisms in their guts to break down the cellulose fibers. Understanding these nuances is crucial for recognizing the feeding habits and behaviors of subterranean termites, which aids in effective pest management and control strategies.