A variety of Insects can tunnel into timber. The most famous culprits are various types of Wood-Boring beetles, but weevils and other Insects are also known to infest wood.
Although the effects of each species vary in their minutiae, general symptoms include visible flight holes between 1-3mm in diameter, although the longhorn beetle can bore holes of up to 9mm.
A Wood-Boring Insect infestation can lead to structural damage in any part of a building's timber. It is advised that it is chemically treated or, in extreme circumstances, the timber may need to be replaced.
Read more about Timber Infestations.