In Edgar Allan Poe's "The Tell-Tale Heart," the unreliable narrator creeps to the old man's chamber to peer upon him while he sleeps for seven nights. On the final fatal night, the narrator fumbles with the tin piece on his lantern, and the old man sits up in bed, listening for an hour. The narrator compares the old man's vigil in the darkness to his own, in which he has sat up "night after night hearkening to the death-watches in the wall."
Death-watches are a type of beetle, which can make a tapping sound, and in more superstitious times, people associated the tapping noise of the death watch beetle as a deathly omen. Poe uses the superstitious nature of the death watch beetle and its eerie tapping sound in the walls of the home as foreshadowing for the thumping of the murdered old man's heart which will later torment the narrator. In fact, Poe leaves the reader wondering what the narrator really heard: the slow, rhythmic tapping of the death watch beetle or the actual murder victim's heart. Perhaps the narrator's paranoia led him to mistake the sound of the insect in the walls for the beating of the "tell-tale heart."