DEATHWATCH
booklouse, book louse, deathwatch, Liposcelis divinatorius
(noun) minute wingless psocopterous insects injurious to books and papers
Source: WordNet® 3.1
Etymology
Noun
deathwatch (plural deathwatches)
A vigil beside a dying person
One who guards a condemned person before execution.
A deathwatch beetle.
Source: Wiktionary
Death"watch` (; 224), n.
1. (Zoöl.)
(a) A small beetle (Anobium tessellatum and other allied species). By
forcibly striking its head against woodwork it makes a ticking sound,
which is a call of the sexes to each other, but has been imagined by
superstitious people to presage death.
(b) A small wingless insect, of the family Psocidæ, which makes a
similar but fainter sound; -- called also deathtick.
She is always seeing apparitions and hearing deathwatches. Addison.
I did not hear the dog howl, mother, or the deathwatch beat.
Tennyson.
2. The guard set over a criminal before his execution.
Source: Webster’s Unabridged Dictionary 1913 Edition