An adult raises its body and knocks the front of its head against the tunnel wall, producing a burst of several rapid taps. A receptive beetle of the opposite sex answers with a matching burst, and the pair converge by repeated exchange through the timber. The sound carries because dry structural wood transmits it well, and it is most audible in quiet old buildings at night, which is how the beetle acquired an association with sitting up with the dying.
The damage is done by the larvae. They tunnel for years in hardwood, and the species depends on wood already softened by fungal decay, so infestation in a building generally signals a damp problem in the timber rather than an isolated insect issue.
Adults emerge through exit holes a few millimetres across, leaving gritty frass. Because the larval period is long and variable, often several years and sometimes far longer in dry timber, the appearance of fresh holes says little about when the timber was first attacked.