cool-critters:

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