A reader wrote to us a week or so ago about some 1/4-inch (quarter-inch) black worms she is finding in the carpet of her house. In addition to being in her carpet, the small black worms are also on the baseboards around her house, which isn’t surprising, given that baseboards often line carpet. The reader says the black worms in her carpet shy away from vacuum cleaners, and also that they seem to prefer darkness over light. What are these small black worms in the carpet of our reader’s home, and how can she prevent these worms from infesting her carpet?
Even without a picture, which is generally essential to a successful creature identification, we are confident that the reader is finding carpet beetle larvae. So, the small black worms are in fact small black larvae. (Almost without exception, people call small insect larvae “worms,” which is understandable, but technically incorrect, at least on certain definitions of the word “worm.”)
Why do we think our reader found carpet beetle larvae? First, carpet beetle larvae are the most common creature we write about on this site. We have received many, many emails about them over the years, and we seem to write about them on about a fortnightly basis. (Indeed, a recent question from a reader about 1/4-inch black worms in her apartment is very similar to the question we are currently addressing.) Thus, we possess a very solid understanding of these creatures and have become good at identifying them, and in addition carpet beetle larvae are very common. Both considerations bolster our carpet beetle larvae hypothesis in this instance.
Moreover, everything the reader said is consistent with her finding carpet beetle larvae. They are about a quarter of inch long, and they do look like black worms. (They are commonly a brown or tan color with dark stripes, but some are essentially black, or at least they could look black if you didn’t examine them up close and under good lighting.) Carpet beetle larvae are also not surprisingly commonly found in carpet, which they consume (along with several non-synthetic fabrics). Finally, carpet beetle larvae do in fact prefer darkness over light. Lots of people don’t even realize they have carpet beetle larvae because for the most part they stay out of the light, preferring dark corners and the spaces under furniture. So, we have a lot of good reasons for thinking our reader found carpet beetle larvae, and essentially no good reason for thinking otherwise. (A picture would help us confirm our strong suspicions, sed non semper erit aestas.)
If our reader is finding carpet beetle larvae, there are definitely preventative measures one can take to avoid the problem in the future. The reader didn’t ask about getting rid of the larvae she currently has in her house, so perhaps she has already taken care of the problem and is merely looking toward the future. Probably the most important preventative measure one can take to stave off a carpet beetle problem is to vacuum frequently and thoroughly, and do this without neglecting the parts of the house that are hard to vacuum, like under furniture. It is also important to keep clothes and other fabrics in use if possible. A pile of clothes (even if they are clean) that is left unmoved for weeks on end could attract carpet beetle larvae, so it is best to keep clothes in circulation so that they are frequently being worn and laundered. The larvae don’t go after synthetic fabrics (unless they are dirty), so this is something to keep in mind when you store materials (e.g., blankets) for long periods of time. Finally, carpet beetle larvae often lay their eggs in insect and bird nests, so if you happen to find these in and around your home, you should probably remove them. At the end of the day, preventing a carpet beetle larvae infestation is essentially about maintaining a clean house. Of course, people with clean houses get carpet beetles, and people with dirty houses often don’t get them, but overall keeping a clean house will be to your advantage.
We hope that we have correctly identified the small black “worms” in the carpet as carpet beetle larvae, and we hope even more that our reader is able to prevent this problem in the future. If she follows our advice, she should be fine.
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