Small Black Worms in the RV

black soldier fly larva
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A reader from Texas recently wrote to us about some small black worms he is finding in his recreational vehicle (“RV”), and sent us a picture of one that is on his floor. On some days, he finds as many as six or seven of the black worms (which can also be “charcoal grey” worms) in his RV, but he has also gone up to a week without finding any worms. After struggling to discern where the worms are coming from, he finally concluded that they are entering the RV through the heat vents. The reader lives in his RV, and so was naturally wondering what he is finding, and he also wanted to know how to get rid of the black worms that have taken up residence in his RV.

First, here is the picture the reader sent us:

black soldier fly larva

The picture is blurry, clearly (or rather not so clearly), but it nevertheless gives us a usable image of the creature in question, which we are reasonably confident is a black soldier fly larva. Since it is a black soldier fly larva, our reader actually isn’t finding worms, despite our earlier use of the word “worms” (which we did to keep with our reader’s usage, although to his credit he did label his picture “the worm or larvae.”)

We have written about black soldier flies (Hermetia illucens) on many different occasions. We have written a fairly thorough overview of black soldier fly larvae, which are also called Phoenix Worms, and we have also received some excellent pictures of black soldier fly larvae from readers. There have been several other occasions that have required us to write about black soldier fly larvae as well. In other words, there is plenty of information about black soldier fly larvae (commonly written as “BSFL”) on the website for our reader to peruse if he is so inclined. The only thing we will note here is that BSFL are largely known because of their role in composting operations, which we mention only because it indicates the type of environment BSFL are primarily found in: piles of decaying organic matter (human-made or natural).

For this reason, BSFL are generally not one of the types of larvae people find in their homes, mobile or otherwise. A reader once wrote to us about a Phoenix Worm in her toilet, but that is the only report we have received about people finding them in their home (although undoubtedly other people have found them in their homes as well). We have no idea what is drawing BSFL into our reader’s RV, but he should be especially mindful of the accessibility of organic waste in his home, which would most likely be found in a garbage can. If there is no food source and suitable habitat for the larvae, they won’t be drawn into the RV. Obviously, our reader will produce waste, but he should be mindful to dispose of it regularly, and if possible any trash that accumulates should be sealed, perhaps in a trash can that has a tight lid.

Our reader should also be mindful about where he parks his RV. If he is near accumulations of decaying organic matter (again, human-made or natural), he might be placing himself in an area in which lots of the larvae are crawling around. The ones that make it into the RV might only be there incidentally – they could be wayward travelers in the area who stumbled into an environment they wouldn’t otherwise be attracted to. This is in fact consistent with our reader’s observation that he only deals with the larvae sometimes. During those weeks when he finds no larvae, perhaps he is away from any potential source of BSFL. Finally, our reader might consider sealing his heat vents a little more thoroughly with some sort of filter. You can never keep every creature out of a home, but if you make it hard for a pest to get inside, they are obviously less likely to find their way in.

We aren’t certain our reader found black soldier fly larvae, but the picture the reader sent in does appear to show a BSFL. And regardless of what he found, he can following our advice to lessen the chances of pests making their way into his home.


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Small Black Worms in the RV
Article Name
Small Black Worms in the RV
A reader from Texas recently wrote to us about some small black worms he is finding in his RV, and sent us a picture of one that is on his floor.

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10 thoughts on “Small Black Worms in the RV

  1. I am and have had the same problem with the worms seam like coming out of completely in my RV I Live in, Been living in one for several years close to my job. In a older camper I had the problem sometimes pretty bad at other times not bad at all. I’ve just started recently having them in my new camper. I m pretty sureI can tie the problem into leaving the sewer valve open which would be nice if you could. But best I can tell that is ABSOLUTELY a NO NO! Waste will build up in Your sewer tank which leads to a lot of problems! I do believe You can eventually ruin your tank leaving your valve open all the time, that tank needs the water level to be there and flush as needed every few days! I can’t stand to see those nasty things in my camper and willing to do about what ever yo get rid of the problem, even if its have to open the valve every few days! In my personel opinion, It would begoodevery so often take a water hose and fill the tank and flush real good to try to get rid of all solids, I DEFINITELY believe you can tie the problem into leaving the valve open all the time or at least too much

  2. I can have same problem, only thing I be have done is used a septic decomposing pack that is suppose to help breakdown waist. Didn’t have this problém prior to using it.

  3. I never saw this black larvaes in my bathroom floor. Where itcame from. I dont know how to rid of black larvaes. I found about several black larvaes crawl on bathroom floor. I hate it

    1. I found these and used Neem oil from Amazon to remove them. Bleach doesn’t kill them and it’s bad to use in an RV. I keep my septic closed always. I empty gray tanks twice weekly and black tank once weekly. I love full time in my RV and use Happy Camper to keep the septic healthy. I treat once a year with Neem and it seems to take care of this issue for my Montana High Country.

  4. All of these comment s have the same problem I do but no one is responding to them with a way to kill them.

  5. I have these in my RV toilet. I live in a mobile home park in the RV, hooked up to their sewer. I had sewer gnats really bad, and would use bleach in the drains to kill them, but lately I have been finding these gross worms in my toilet. They wash down from where the fresh water comes in, around the top of the toilet. I have to splash the bleach up there, or use a sprayer to get it up there, but is there any way to stop them? Every time I think they are gone, there they are again!!

  6. Our RV toilet was full of this BSFL larvae. Just found them today when cleaning the RV. I’ve seen a video and I know that’s what I found. Also the flies were in the shower flying around and I killed them. We flushed the larvae and I cleaned the toilet with bleach water but some of the larvae are stuck in the rubber rim of the toilet. I tried to remove them with a toothbrush but could not get them all. What else can I do and how did this happen and how can we prevent it from happening again ? And are these things harmful to us ? Would they be in our freshwater tank as well ? I’m clueless and need help here ! Thanks !

  7. 2 black flat worms in my rv toilet this morning . The toilet was stopped up so I had to work on it this morning . These two worms ,looking like leeches were flat not round .they were about 1 1/4″ long.

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