A reader recently sent us a photo of a short, fat brown worm via the All About Worms Facebook page. He asked one simple question: “what kind of worm is this?” Given some of the complex and convoluted questions we receive, we welcomed this beautifully straightforward message. We are tasked with one question – what is the short, fat brown worm that our reader found? – and were sent an excellent photo of the worm under consideration, making our job as easy as it could be.

Here is the picture our reader submitted:

We have been describing this creature as a short, fat brown worm, but only to keep with the wording of our reader’s question. In fact, what he found is a type of larvae; more precisely, he almost certainly found a black soldier fly larvae (BSFL), a relatively common creature we have written about on a number of occasions. BSFL are occasionally called Phoenix Worms, a name given to the creatures by Dr. Craig Sheppard, who started selling the larvae as feeder insects. Generally people buy them to feed to small pets like reptiles, although a variety of animals will eat them. (One reader informed us that black solider fly larvae are like M&Ms to his chickens. We encourage the reader to whom we are presently responding to check out this article. There are several pictures of BSFL larvae, and they look almost identical to the creature pictured above.)

In addition to serving as animal feed, BSFL are also used in composting operations. Indeed, apart from red worms, they are probably the most common “worms” used in compost bins. They are able to operate in hot environments, and they are also able to maintain a pure and efficient compost bin by preventing other flies from laying eggs in the decaying organic matter. Despite these virtues, you might think that it is risky to run a composting operation with larvae that will quickly mature into obnoxious flies, but fortunately black soldier flies aren’t that obnoxious. In stark contrast to houseflies, they don’t fly around very much, and they are easy to relocate because they don’t mind being touched. (They don’t bite or sting, so they are for the most part harmless to touch, although it is always good to be careful when touching insects and larvae because of the pathogens they may carry.)

If our reader is interested in reading more about the short, fat brown “worm” he found, he should review the articles we have already linked to, and he might also enjoy our overview of black soldier flies.