A woodboring beetle whose grubs eat old hardwood structural timbers. Practically a status symbol for owners of stately homes in which the beetle family has probably lived since they were built.
Adults rarely fly, so infestations are diminishing as old buildings are either treated or demolished. The death watch beetle does not like modern softwood house timbers.
Grubs live up to ten years inside timber, emerging as mottled grey/brown beetles about 7mm long, through exit holes about 4mm in diameter. When adult, they produce a rapid tapping sound by beating their heads against the wood as a mating call.
REMEDY: Persistent and thorough use of a proprietary woodworm killer will deal with small outbreaks, or call in a wood preservation company.