Any one of several beetles of the family Anobiidae, especially Xestobium rufovillosum, whose head makes a clicking sound as it burrows into wood or wooden structures. The sound was superstitiously regarded as a portent of death. Borer insect (beetle species Xestobium refuvillosum) that tends to be small (less than 0.5 in., or 1-9 mm) and cylindrical. When disturbed, it usually pulls in its legs and plays dead. It makes a ticking or clicking sound by bumping its head or jaws against the sides of the tunnels it creates as it bores into old furniture and wood, a sound that, according to superstition, forecasts a death