Deathwatch Beetles: Bad Omens In The Night? Nope, They’re Just Horny

You’re all alone. It’s dark. It’s near-silent – except for a quiet, rhythmic tapping that seems to be coming from inside the walls. The creature making that sound? The deathwatch beetle (Xestobium rufovillosum), and if some tales are to be believed, its soft patter is a harbinger of death.

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That is, however, absolute nonsense. Enjoyable nonsense, for those of us who may be scientifically minded but love a superstitious tale or two, but nonsense nonetheless.

It’s also nonsense that’s been around for a long time. There are numerous cultural references to the deathwatch beetle as a sign that someone is about to meet their demise, dating back hundreds of years. One of the earliest mentions comes courtesy of 17th-century polymath Thomas Browne, who mentioned the insect in his work on common errors and superstitions, Pseudodoxia Epidemica. 

More recently (at least 1995 feels like it should be recent, and not 30 years ago), the book and subsequent film Practical Magic sees main character Sally Owens hear the tap-tap-tapping of the beetle shortly before her husband is killed in a car accident.

It’s understandable that people might make a superstitious association with the beetle’s sound. The tapping is often heard when it’s dark and quiet, in old houses, the kind of setting in which people may have been sitting silently with the sick or dying, and that gets your brain and body primed to be on edge and vigilant to unexpected sights and sounds.

But the quiet tapping of the deathwatch beetle is not a warning that someone you know is about to pop their clogs. Beetles have many impressive abilities, but accurate prediction of death isn’t one of them.

Instead, the only thing that the deathwatch beetle is a bad omen for is the wood in your house. Hearing its tapping means it’s hanging out near your wooden beams, furniture, or flooring – and that it’s ready to make little baby beetles.

The tapping sound comes from male deathwatch beetles whacking their head or jaws against the wood, which is how they communicate to the females, “Hello, I’m here and available.” If they’re up for it, females tap back, which the males then use to locate their potential mates.

After a successful union, females then lay their eggs in holes and crevices in the wood, and when the larvae hatch, the destruction begins. In a period that can last anywhere from one to 13 years, the larvae make their way through the wood, causing major damage as they go, and when they bore their way out of the wood as adults too.

So, if you hear a deathwatch beetle in your wall, it’s not a sign that you should check in with your loved ones – you’d be better off checking in with pest control.