Hearing mysterious clicking sounds at night is a common experience, often leading to curiosity about their origin. These nocturnal noises frequently come from the insect world, serving various purposes for the creatures that produce them. Understanding these sounds can help demystify the natural symphony of the night.
The Usual Suspects Behind the Click
Among the most frequent producers of nocturnal clicking sounds are two specific types of beetles: click beetles and deathwatch beetles. Click beetles, belonging to the family Elateridae, are slender and elongated, typically brown or black, ranging in size from about 0.25 to 2.5 inches. Their characteristic “click” is made when they right themselves after being overturned.
Deathwatch beetles, members of the family Ptinidae, are smaller, usually 0.1 to 0.3 inches long, with a cylindrical body and a mottled brown appearance. Their head is often concealed by a thoracic shield. Unlike click beetles, deathwatch beetles produce a distinct tapping or ticking sound, often heard within older wooden structures. While other insects like crickets, katydids, and cicadas produce sounds at night, their chirps, trills, or buzzes are generally distinct from the sharp clicks or rhythmic taps of these beetles.
Understanding the Click’s Purpose
The clicking sound produced by click beetles serves a specific survival mechanism. When a click beetle finds itself on its back, it uses a unique internal hinge-like mechanism to flip itself upright. A spine on its prosternum snaps into a corresponding notch on its mesosternum, creating a sudden, forceful release of energy. This action propels the beetle into the air, often with an audible click, allowing it to land back on its feet. This rapid movement also helps to startle potential predators, acting as a defense mechanism.
For deathwatch beetles, the tapping sound has a different, yet equally purposeful, function related to communication and reproduction. Adult deathwatch beetles produce their distinctive ticking by repeatedly banging their heads against the wood surface. This percussive sound serves as a mating call, primarily used by males to attract females. Females respond to these taps, allowing the males to locate them for mating. This form of communication is crucial for their life cycle, which often occurs within the confines of wooden structures.
Pinpointing the Source of the Sound
Differentiating and locating the source of nocturnal insect sounds involves paying attention to their quality and context. Click beetles produce a sharp, singular “snap” or “click” as they flip, which is often heard when they land on a hard surface or encounter an obstacle. These sounds can come from almost anywhere, including near windows or light sources, as adult click beetles are often attracted to light at night.
Deathwatch beetles, in contrast, create a rhythmic “tap-tap-tap” or “tick-tick-tick” sound, which can resemble an old clock. This sound typically emanates from within wooden structures, such as walls, ceilings, or furniture. The tapping is often more noticeable in quiet environments when the beetles are most active. Detecting small, round exit holes, 2 to 4 mm in diameter, in wooden beams or furniture, along with fine, powdery sawdust (frass), can further confirm the presence of deathwatch beetles.
Coexisting or Controlling Nocturnal Clickers
Most clicking insects, particularly click beetles, are generally harmless to humans and property. Adult click beetles do not bite or sting. While their larvae (wireworms) can be agricultural pests, they do not typically damage homes. Their presence indoors is often accidental, as they are attracted to lights. Simple tolerance or gently relocating them outdoors is usually sufficient.
Deathwatch beetles, however, can indicate a potential issue within wooden structures. Their larvae bore tunnels through wood, consuming cellulose and hemicellulose, which can weaken timbers over many years. While the damage is slow and requires damp, often fungus-affected wood, persistent tapping from within structural wood might warrant further investigation. Addressing moisture issues and ensuring proper ventilation can help prevent or mitigate infestations. For significant infestations, consultation with a pest control professional specializing in wood-boring insects may be appropriate.