We received an excellent photo a while ago of what a reader described as two large groupings – or “packs” – of small white worms or larvae that were formed in lines. Since we are pretty certain she found fungus gnat larvae, or more specifically what are sometimes called “fungus gnat larvae snakes,” we will refer to them only as “small white larvae,” and not hedge by writing “small white larvae or worms.” The reader found the lines of white larvae – or we suppose they are actually more like see-through larvae with black heads – on her concrete patio, and was merely wondering what they are. As we said above, they look like gnat fly larvae, so the reader’s question has technically already been answered, but below we provide a little more information about these strange configurations of creatures. What exactly are fungus gnat larvae, and why do they group together to form “snakes.”
For obvious reasons, you might be having trouble picturing how a group of small larvae can resemble a snake. Fortunately, though, the reader sent in a good picture:
ATTENTION: GET PARASITE HELP NOW! At All About Worms we get a lot of questions about skin parasites, blood parasites, and intestinal parasites in humans. Because we can't diagnose you, we have put together this list of doctors and labs who understand and specialize in dealing with parasites in humans! That resource is HERE
Although a clear picture, this only captures a body segment of the snake, as it were. We have no idea exactly what the form and size of reader’s larvae grouping were, but in general fungus gnat larvae, when they decide to band together, look remarkably like a snake. Their bodies all face the same direction, and the length of the grouping is many times greater than its width. Moreover, the larvae all move together as one unit, as if a snake is somehow pushing itself forward without slithering. It is a very strange phenomenon.
However, fungus gnat larvae are not always found in this configuration, as the snakes are generally only seen during especially wet years or in wooded areas, according to the University of Maryland Extension Program. (We don’t know if it’s been a wet year wherever our reader lives, but obviously she didn’t find her fungus gnat larvae in a wooded area. In any case, we are sure the snakes have been seen in a variety of circumstances.) Also, only some species of fungus gnat, like the so-called “dark-winged fungus gnats,” arrange themselves in these groupings when they are larvae.
|No Paywall Here!
All About Worms is and always has been a free resource. We don't hide our articles behind a paywall, or make you give us your email address, or restrict the number of articles you can read in a month if you don't give us money. That said, it does cost us money to pay our research authors, and to run and maintain the site, so if something you read here was helpful or useful, won't you consider donating something to help keep All About Worms free?
If people have seen these creatures before, they likely saw them as adults – in the form of fungus gnats, of course. However, the larvae are often found in potted plants, which contain soil that is loaded with organic matter, so they appear from time to time as well. They obviously are found in regular, outdoor soil as well, but people are less likely to see them there. The larvae are especially prevalent in moist soil, as water stimulates the growth of fungi, which is what the larvae feed on, and hence their name.
A certain identification is not something we can offer very often, and it’s possible that our reader found something else, but we are quite confident our reader is finding fungus gnat larvae. The larvae are harmless, as are the adults the larvae grow into, so hopefully our reader just enjoyed the sight (insofar as this was possible) and let the larvae go on their way.