However, foundation cracks, voids in hollow cement blocks and unbended stucco can provide the termites with hidden accesses to their source of food, in this case, the structure. Subterranean termite colonies are huge, can cover areas a block in size and the colony can number in the millions, all hidden from easy view. Fumigation is never used as a control. They are difficult to detect. The rate of destruction is low.
Colonies start with a single king and queen and develop slowly over the years.
It might take seven years to grow to a population of l,OOO nymphs, soldiers and the king and queen. A colony of this size might eat only one-half pound of wood in a year. It takes many years before dried termites do significant harm to a structure. Evidence of infestation can be visual. Noting entrance and exit holes is another.