Animals that gnaw timber in buildings

In the forest, trees are attacked by many different kinds of animal. There are some which eat the leaves, but in the context of the present book we are more interested in those insects which attack the timber itself. Some of these attack only healthy, living trees, whereas others specialize exclusively in weakened or dead trees. Certain species live only in the growth layer immediately beneath the bark, whereas others penetrate right into the sapwood and the heartwood. Among those which attack dead trees, some species live in dry timber, and in the wild these will be found in dry branches or dead trunks which remain standing, whereas others will only thrive in damp, rotting timber.

When man began to use timber from the forest for equipment and houses certain of these insects must have entered his home. Some of them are merely transferred from the forest as eggs or larvae, and cannot live in timber that has been worked.

The species which had the most chance of survival, and which have become serious pests of timber, were those which could thrive in dry wood, for this is what is used in houses. In addition, there are several species which occur in places where timber structures have been damaged by damp and by fungus.