A reader wrote to us a while ago inquiring about what types of worms smell bad. The reader and her son were in the kitchen when they noticed “something smelled funny.” After looking around for a while, they finally discovered the source of the bad smell: a small worm, or what looked like a worm. The reader seemed surprised by this – the worm smelled “awful and very strong” – and was wondering what kinds of worms smell bad.
The reader herself indicated that the small worm might not be a worm at all, and we think she is right. We suspect the foul-smelling “worm” is in fact a millipede, an arthropod with two legs per body segment. We suspect this is what our reader is finding because millipedes are the only worm-like creatures that we know of that routinely smell bad, and in fact we have written an explanation of why millipedes smell bad in the past. Millipedes are also quite common, and it wouldn’t be at all unusual to find them in your house.
The odor emitted by millipedes is a defense mechanism. Their glands secrete foul and even poisonous fluids to dissuade predators from attacking them. This may not seem very threatening to us, but it would be to, say, a spider trying to attack it. In general, a millipede will only smell bad when it is threatened – this is the only time when it needs to exercise its defense mechanism – so we aren’t sure exactly why the millipede in our reader’s house (if it was a millipede) smelled bad. Perhaps our reader inadvertently threatened it as she was walking around her kitchen, or perhaps the millipede was battling some other predator, causing it to release an odor.
Given that millipedes are common household creatures that smell bad, we think there is a fairly good chance that the foul-smelling worm our reader found is actually a foul-smelling millipede. The reader did describe what she found as a worm, which a millipede is not, but she conceded that it may only look like a worm, and a millipede can look a lot like a worm, especially if its legs aren’t visible. Although our reader shouldn’t be alarmed by the presence of the millipede or its unfortunate smell, she should exercise some caution in removing it from her home. In addition to smelling quite bad, the fluids that millipedes secrete can also cause skin irritation or allergic reactions. So, she shouldn’t pick the millipede up with uncovered hands, not that one’s first reaction upon finding a “worm” that smells bad is to pick it up. Hopefully our reader and her son won’t be confronted by a terrible smell the next time she enters her kitchen.