We recently got this message from a reader, “I found 3 small black worms in the toilet in my camper so I am wondering what they are and if they are harmful towards me or my family?” The first photograph is a little blurry. It shows a black worm-like organism in a toilet bowl:

Even though the photograph isn’t super clear, we still believe we can identify this organism with confidence. Although there are many black worm-like organisms that might look similar to the creature in the photo, the fact that we know where our reader found the specimens gives us a huge hint. What black worm-like organisms feed on organic waste and might be found in a toilet? Well, the two most common creatures are drain fly larvae and black soldier fly larvae. We know he isn’t dealing with drain fly larvae because they are much smaller and have more translucent bodies than the mystery creature. So, that leaves us with black soldier fly larvae, and after looking at the second photograph our reader sent, we are absolutely confident that its a match!

Black soldier fly larvae, or BSFL for short, are common fly larvae found throughout the world. As far as worm-like organisms go, BSFL have a glowing reputation. They are excellent decomposers and can be found in compost piles breaking down organic substrates and returning nutrients to the environment. They are also used as a protein source for farm animals, and some people even breed BSFL in colonies for these purposes! Finally, they aren’t considered a pest or vector species (as in they don’t transmit or carry human diseases) so they won’t be harmful towards our reader or his family.

Returning his toilet to a BSFL-free zone will just require that our reader give the toilet a thorough cleaning. He will need to scrub the bowl thoroughly in order to eliminate all of the built up organic matter, which is what the BSFL are feeding on. He should use a toilet cleaning brush and a cleaning agent targeted at eliminating organic material. Once their food source is gone, the BSFL shouldn’t be a problem for our reader anymore!

To wrap up, one of our readers found three black worms in his toilet. We are confident these are black soldier fly larvae! Since they feed on organic waste, our reader will just need to clean his toilet to get rid of them.