“What are these?” is all Judah asks in his submission regarding the translucent worm-like creatures pictured below. The creatures seem to have black heads and a dark stripe on their bodies, which, given their translucent skin, appears to be their entrails. Even though Judah does not provide any context along with his photo, which is usually essential to us narrowing down a given creature’s possible identities, we are able to identify these critters based on their appearance. We think these are fungus gnat larvae.

Fungus gnats, otherwise known as sciarid flies, are a species of fly that tend to invade potted compost such as houseplants. Their larvae will live in the soil and eat fungal growths, cuttings, and seedlings. Because of their taste for cuttings and seedlings, some consider fungus gnats larvae pests, as they can cause damage to young plants when large numbers of them are present. However, fungus gnat larvae do not really cause significant or permanent damage to a plant, so infestations of them are more of a nuisance than anything else.

These creatures typically do travel together, and sometimes will even move as one entity, piling on top of each other to form one long worm train. In fact, we have covered the phenomenon of “the fungus gnat larva train” before. So, unless Judah found these inside his home, which, based on the picture, we don’t think is the case, then we do not think he needs to be worried about an infestation. These larvae are likely traveling somewhere that will provide a safe and damp environment for them to pupate.

That said, if he does find them inside one of his houseplants, then that houseplant should be re-potted, with any roaming larvae picked off and moved outside. On top of that, it might be a good idea to isolate the plant from other houseplants, so as to prevent further spread of the infestation. Additionally, to prevent future infestations of houseplant-loving bugs, make sure to use fresh soil when potting and re-potting houseplants, and spray the leaves with slightly soapy water during the warmer seasons to keep bugs from climbing them.

In conclusion, we think that the worm-like creatures Judah found are fungus gnat larvae. The most harm they can do is to seedlings and cuttings, but they are completely harmless to humans and pets, so Judah needs not worry about this. We hope this helps and we wish him the very best!

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