The deathwatch beetle was the type of insect that Saint Nymphadota lived on for thirty years while living in a hollow tree (Saint Fidgeta and Other Parodies, 84).


The deathwatch beetle is a woodboring beetle. To attract mates, these woodborers create a tapping or ticking sound that can be heard in the rafters of old buildings on quiet summer nights. They are therefore associated with quiet, sleepless nights and are named for the vigil kept beside the dying or dead, and by extension the superstitious have seen the deathwatch beetle as an omen of impending death[1].


  1. Wikipedia: Deathwatch beetle