Deathwatch beetle (Xestobium rufovillosum)
The deathwatch beetle is a species of woodboring beetle that sometimes infests the structural timbers of old buildings. The adult beetle
is brown and measures on average 7 mm long. Eggs are laid in
dark crevices in old wood inside buildings, trees, and inside tunnels
left behind by previous larvae.
The larvae bore into the timber, feeding for up to ten years before
pupating, and later emerging from the wood as adult beetles. The larvae of deathwatch beetles weaken the structural timbers of a building by tunneling through them. To attract mates, the adult insects create a tapping or ticking sound
that can sometimes be heard in the rafters of old buildings on summer
nights; therefore, the deathwatch beetle is associated with quiet,
sleepless nights and is named for the vigil
(watch) being kept beside the dying or dead. By extension, a
superstition has grown up that these sounds are an omen of impending
death.
photo credits: Sarefo, Gilles San Martin