It is unclear, however, if the narrator actually has very acute senses or if he is merely imagining things. If his condition is believed to be true, what he hears at the end of the story may not be the old man's heart but death watch beetles. The narrator first admits hearing death watches in the wall after startling the old man from his sleep. According to superstition, death watches are a sign of impending death. One variety of death watch beetles raps its head against surfaces, presumably as part of a mating ritual, while others emit a ticking sound.